Brake fluids -Dot 5?

B

Bob Dunahugh

New member
Sep 17, 2012
2,784
4
3
It depends on what you are doing to the system at this point. Plus. What are your interest in DOT 5. Each type of brake fluid. Have different attributes. For me. My GVW is sometimes at 24,000 lbs with our 78 Royale. So I install Ford's DOT3 High Performance brake fluid. ( Only at Ford dealers. ) That Ford put in their trucks. That were slated for MH use. As it's boiling point is much higher then standard DOT 3. The Feds have a minimum boiling point for DOT 3. That must be met. Ford,s is just way higher, I use it for my road racing. I have some photo's that were taken by a friend. Of my Yenko, at dusk. The drums were glowing. As I have segmented iron brake shoes. I change fluid everyday. Some like DOT 5. Because they feel it can be used for more years. All brake fluids should be changed every 5 years. On our GMC. Every 4 years. WHY. Because I love our Royale. And us.
Bob Dunahugh
78 Royale since 2003
4 COPO Yenkos
 
Thanks Bob for getting back. I had my brakes a couple of years ago and was thinking I needed to change out brake fluid here but looks like I have a
couple more years yet. The DOT 5 consideration was because of its higher boiling point and also its stability pertaining to water absorption. I
would like to check into Fords brake fluid when the time comes.

Thanks,
Tom
 
Tom
Check into5.1 it has as high a boiling point as 5.0 and has other advantages. I have now installed it in 6 GMC’s for friends

Emery Stora

>
> Thanks Bob for getting back. I had my brakes a couple of years ago and was thinking I needed to change out brake fluid here but looks like I have a
> couple more years yet. The DOT 5 consideration was because of its higher boiling point and also its stability pertaining to water absorption. I
> would like to check into Fords brake fluid when the time comes.
>
> Thanks,
> Tom
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
 
Tom. DOT min boiling point is 284 F (140 C ). Ford is 500 F (205 C) Water absorption was a big deal prior to about 1960 I believe. In that time frame. Systems became much more sealed. You see brake system that are 40 years old. And still have never been change. Brake lines rust from the outside. Some owners believe SS lines need to be installed for corrosion protection. Fine. As a note. SS lines are very hard. Thus getting them to seal at the brass fittings can be an issue. With standard steel lines. Those lines will out live you. Get those rubber brake hoses changed.
Bob Dunahugh
78 Royale since 2003
4 real COPO Yenkos

________________________________
From: Bob Dunahugh
Sent: Wednesday, May 27, 2020 1:16 AM
To: gmclist
Subject: Brake fluids -Dot 5?

It depends on what you are doing to the system at this point. Plus. What are your interest in DOT 5. Each type of brake fluid. Have different attributes. For me. My GVW is sometimes at 24,000 lbs with our 78 Royale. So I install Ford's DOT3 High Performance brake fluid. ( Only at Ford dealers. ) That Ford put in their trucks. That were slated for MH use. As it's boiling point is much higher then standard DOT 3. The Feds have a minimum boiling point for DOT 3. That must be met. Ford,s is just way higher, I use it for my road racing. I have some photo's that were taken by a friend. Of my Yenko, at dusk. The drums were glowing. As I have segmented iron brake shoes. I change fluid everyday. Some like DOT 5. Because they feel it can be used for more years. All brake fluids should be changed every 5 years. On our GMC. Every 4 years. WHY. Because I love our Royale. And us.
Bob Dunahugh
78 Royale since 2003
4 COPO Yenkos
 
What Emery said. Since the introduction of 5.1 5.0 has no real benefit but
brings more hassle.

Sully
Bellevue wa.

On Wed, May 27, 2020 at 9:47 AM Emery Stora via Gmclist <

> Tom
> Check into5.1 it has as high a boiling point as 5.0 and has other
> advantages. I have now installed it in 6 GMC’s for friends
>
> Emery Stora
>
> > On May 27, 2020, at 9:29 AM, tom geiger via Gmclist <

> >
> > Thanks Bob for getting back. I had my brakes a couple of years ago and
> was thinking I needed to change out brake fluid here but looks like I have a
> > couple more years yet. The DOT 5 consideration was because of its
> higher boiling point and also its stability pertaining to water
> absorption. I
> > would like to check into Fords brake fluid when the time comes.
> >
> > Thanks,
> > Tom
> >
> > _______________________________________________
> > GMCnet mailing list
> > Unsubscribe or Change List Options:
> > http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>
 
In the early days of DOT5, I converted several antique and classic vehicles to it. Because an automotive chemist friend (I had not yet met Emery)
told me about the material incompatability, because elastomers all have some permeability of lots of things and it can be cumulative he suggested that
I not change, but convert the system by replacing all the elasomer (like rubber) parts. I did that on some, but not all. Those where I did not
replace everything turned out to be leaking and terrible things in later years. This was only cured by rebuilding the entire system.

Also in later years, one vehicle that I did keep for myself had wheel cylinder trouble. I found a line of rust in the bottom of some wheel cylinders.
Again, my ties with the automotive engineering world got me a lot of information. It turns out that the hydraulic seals used in automotive breaks
are all about keeping the hydraulic fluid in (surprise?) but in doing that, they are not great at keeping water out. Before a hydraulic fluid with
near zero miscibility for water came along, this was no big issue. Water got in, but nobody really knew how that happened. It is why GM went to the
diaphragm sealed master cylinder.

Now, with DOT5, the water could be sequestered in the wheel cylinders and there was nothing to prevent local corrosion. This is why you should think
about flushing the brakes of a long lived vehicle. It is the only way to prevent expensive damage.

Speaking of expensive, one of those vehicles with a rusted wheel cylinder was an strange and the wheel cylinders by part number were NLA. I now
needed two. The two were different. I had to get something that was close to one and remachine the mounting so it could bolt to the backing plate and
then rebore it to the correct size. Fortunately a rebuild kit was available. The other I put a SS sleave in. Being able to buy new wheel cylinders
is so nice.

I now have a "Guess the moisture" probe that I get out when doing a vehicle service. I have not had it long enough to venture an opinion as to its
value.

Matt
--
Matt & Mary Colie - '73 Glacier 23 - Members GMCMI, GMCGL, GMCES
Electronically Controlled Quiet Engine Cooling Fan
OE Rear Drum Brakes with Applied Control Arms
SE Michigan - Twixt A2 and Detroit
 
First British car I worked on with Girling Disc brakes, was a Triumph
roadster, a TR-2 if memory serves. Those brakes used Mineral Oil as brake
fluid. This one was leaking from every place possible, and the owner wanted
it fixed. He was a purist, and fussed over every detail. He wanted it ALL
ORIGINAL. I told him if he insisted on using that Girling fluid, that he
could load it up and take it down the road. He went to a local BMC repair
shop, and they quoted him some unbelievable price to fix his brakes. So, he
came back and asked what we could do to fix his brakes. I checked with my
local supplier, and every rubber part in that system was available from
Lockheed in modern D.O.T. 3 compatible stuff. So that is what we did.
Rebuilt every part of that system. I personally think it worked better than
the Girling stuff, a whole lot cheaper, too. Your experience may differ.
Jim Hupy
Salem, Oregon

On Thu, May 28, 2020, 12:15 PM Matt Colie via Gmclist <

> In the early days of DOT5, I converted several antique and classic
> vehicles to it. Because an automotive chemist friend (I had not yet met
> Emery)
> told me about the material incompatability, because elastomers all have
> some permeability of lots of things and it can be cumulative he suggested
> that
> I not change, but convert the system by replacing all the elasomer (like
> rubber) parts. I did that on some, but not all. Those where I did not
> replace everything turned out to be leaking and terrible things in later
> years. This was only cured by rebuilding the entire system.
>
> Also in later years, one vehicle that I did keep for myself had wheel
> cylinder trouble. I found a line of rust in the bottom of some wheel
> cylinders.
> Again, my ties with the automotive engineering world got me a lot of
> information. It turns out that the hydraulic seals used in automotive
> breaks
> are all about keeping the hydraulic fluid in (surprise?) but in doing
> that, they are not great at keeping water out. Before a hydraulic fluid
> with
> near zero miscibility for water came along, this was no big issue. Water
> got in, but nobody really knew how that happened. It is why GM went to the
> diaphragm sealed master cylinder.
>
> Now, with DOT5, the water could be sequestered in the wheel cylinders and
> there was nothing to prevent local corrosion. This is why you should think
> about flushing the brakes of a long lived vehicle. It is the only way to
> prevent expensive damage.
>
> Speaking of expensive, one of those vehicles with a rusted wheel cylinder
> was an strange and the wheel cylinders by part number were NLA. I now
> needed two. The two were different. I had to get something that was close
> to one and remachine the mounting so it could bolt to the backing plate and
> then rebore it to the correct size. Fortunately a rebuild kit was
> available. The other I put a SS sleave in. Being able to buy new wheel
> cylinders
> is so nice.
>
> I now have a "Guess the moisture" probe that I get out when doing a
> vehicle service. I have not had it long enough to venture an opinion as to
> its
> value.
>
> Matt
> --
> Matt & Mary Colie - '73 Glacier 23 - Members GMCMI, GMCGL, GMCES
> Electronically Controlled Quiet Engine Cooling Fan
> OE Rear Drum Brakes with Applied Control Arms
> SE Michigan - Twixt A2 and Detroit
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>
 
After three Bugeyes and one Spridget, I found something nice to say about British brakes. They don't fail as often as Lucas electrics.

--johnny

--
Foolish Carriage, 76 26' Eleganza(?) with beaucoup mods and add - ons.
Braselton, Ga.
I forgive them all, save those who hurt the dogs. They must answer to me in hell
 
Emery, am I correct that I can replace the 3.0 with 5.1 on my coach without worrying about incompatibility? I don't want to take it apart again if I
can help it. Three years ago I did rear cylinders and shoes, it had newer lines and good drums. Recently I put 80 MM calipers and lines on the
front. And I wonder if I'm bleeding them properly. I've a borrowed Hupy bleeder, how much fluid should I run through to be reasonably sure I have
the air out? I also wonder if I'm adjusting them too loosely? Wouldn't matter ona tandem but with four sets, you could run out of pedal before you
run into the drums. I feel like either they're too far out or theree's air in the system. When it hits the discs about halfway down, it's solid.

--johnny

--
Foolish Carriage, 76 26' Eleganza(?) with beaucoup mods and add - ons.
Braselton, Ga.
I forgive them all, save those who hurt the dogs. They must answer to me in hell
 
5.1/3/4 all compatible.

Sully
Bellevue wa

On Fri, May 29, 2020 at 9:11 AM Johnny Bridges via Gmclist <

> Emery, am I correct that I can replace the 3.0 with 5.1 on my coach
> without worrying about incompatibility? I don't want to take it apart
> again if I
> can help it. Three years ago I did rear cylinders and shoes, it had newer
> lines and good drums. Recently I put 80 MM calipers and lines on the
> front. And I wonder if I'm bleeding them properly. I've a borrowed Hupy
> bleeder, how much fluid should I run through to be reasonably sure I have
> the air out? I also wonder if I'm adjusting them too loosely? Wouldn't
> matter ona tandem but with four sets, you could run out of pedal before you
> run into the drums. I feel like either they're too far out or theree's
> air in the system. When it hits the discs about halfway down, it's solid.
>
> --johnny
>
> --
> Foolish Carriage, 76 26' Eleganza(?) with beaucoup mods and add - ons.
> Braselton, Ga.
> I forgive them all, save those who hurt the dogs. They must answer to me
> in hell
>
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>
 
Yes, 5.1 is completely compatible with your existing fluid.

Suck the brake fluid from th master cylinder and fill with Dot 5.1. Open the right rear bleeder. You can see if it will gravity bleed. Be sure to use a clear tube from the bleeder to the collection bottle so you can see air bubbles. If the fluid runs clear go to the other brake on that side. If they won’t gravity bleed use a bleeder or have someone push on the brakes. I prefer to use a vacuum bleeder.

Then bleed the right side, then the right front and last the left front. It shouldn’t take more than 1 to 1-1/2 pints.
The amount of clearance on the shoes shouldn’t reale to air in the system. Turn the adjusting “stars” while turning the wheel until you just feel a drag.

Emery Stora
77 Kingsley
Frederick CO

>
> solid.
>
> --johnny
 
The Dot 3, 4 and 5.1 are all compatible with each other. I have only know of 1 person that ran the Dot 5 silicon fluid in his brake system and that was Don Wirth who many of you knew from days gone by. Dot 5 does not absorb water, but will allow it to collect in your brake system after a while. It is an absolute pain in the butt to change over to. Requires that all the rubber parts be rated for the silicone brake fluid and typically you end up changing all the rubber out, replacing all the slave cylinders and or calipers out for new and flushing and drying all the brake lines and oh yes you will need to change the combo valve too. Too much pain for so little gain!

I have run for the last 20 years run a Dot 3/4 brake fluid. I have been using the Valvoline synthetic Dot 3 & 4 Brake fluid without any issues.

https://shop.advanceautoparts.com/p/valvoline-dot-3-and-4-brake-fluid-12-oz.-601457/89016680-P?searchTerm=brake%20fluid

I thoroughly check my brake system every year and flush every 2 years. It usually takes about 2 of the large bottles (32 oz) to do it correctly and I use a vacuum bleeder to finish and start out just doing a gravity bleed first to get the majority of the air out of the systems. Always start at the farthest away brake and work your way to the closes to the Master.

I will be changing to the Wagner Dot 5.1 Severe Duty Brake Fluid this summer as I will have time to do a number of maintenance and small projects with the coach parked.

Advanced Autoparts:
https://www.powersportsid.com/wagner/dot-5-1-brake-fluid-mpn-fc133301.html?view=429306&utm_source=microsoft&utm_medium=cpc&utm_campaign=268680876&utm_content=1176478073060724
or Amazon:
https://www.amazon.com/Wagner-Dot-SEVEREDUTY-Brake-Fluid/dp/B000C92RDC/ref=asc_df_B000C92RDC/?tag=bingshoppinga-20&linkCode=df0&hvadid=&hvpos=&hvnetw=o&hvrand=&hvpone=&hvptwo=&hvqmt=e&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=&hvtargid=pla-4584413737342657&psc=1

J.R. Wright
GMC Great Laker MHC
GMCGL Tech Editor
GMC Eastern States Charter Member
GMCMI
78 GMC Buskirk 29.5’ Stretch
75 GMC Avion (Under Reconstruction)
Michigan

>
> 5.1/3/4 all compatible.
>
> Sully
> Bellevue wa
>
> On Fri, May 29, 2020 at 9:11 AM Johnny Bridges via Gmclist <

>
>> Emery, am I correct that I can replace the 3.0 with 5.1 on my coach
>> without worrying about incompatibility? I don't want to take it apart
>> again if I
>> can help it. Three years ago I did rear cylinders and shoes, it had newer
>> lines and good drums. Recently I put 80 MM calipers and lines on the
>> front. And I wonder if I'm bleeding them properly. I've a borrowed Hupy
>> bleeder, how much fluid should I run through to be reasonably sure I have
>> the air out? I also wonder if I'm adjusting them too loosely? Wouldn't
>> matter ona tandem but with four sets, you could run out of pedal before you
>> run into the drums. I feel like either they're too far out or theree's
>> air in the system. When it hits the discs about halfway down, it's solid.
>>
>> --johnny
>>
>> --
>> Foolish Carriage, 76 26' Eleganza(?) with beaucoup mods and add - ons.
>> Braselton, Ga.
>> I forgive them all, save those who hurt the dogs. They must answer to me
>> in hell
>>
>>
>> _______________________________________________
>> GMCnet mailing list
>> Unsubscribe or Change List Options:
>> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
 
How funny Jim H. The car I mention I got the Dot 5 suggest on their forum was a Triumph TR6. The brakes are the last item from the winter list I had
to do. And of course they are giving me the most trouble. Once I get it flushed then I’ll be ready to drop it back on its feet again.
Dot 3 is what I decided to go with so I think I’m close with that. Too funny on the Lockheed reference too. Had work with them for a extended
period at the engineering firm I worked at. Small world kinda.

Tom
 
Early British cars ( before 1972) had the Prince of darkness ( Lucas )
Electrical systems, and Mineral Oil Brake fluid. Then came US regulations
on emissions and Low speed crash resistance. Beautiful "nerf" style bumpers
went away, and "crash resistant" Butt Ugly telescoping bumpers were hacked
on, raised the price as well as the weight. Mineral Oil brake fluid gave
way to D.O.T. 3. Roll over protection, safety "A" pillars, and Emission
equipment taxed those British and other European cars right out of the
export business. Only the strong survived. AUDI, VW, VOLVO, etc.
The Japanese were lying in the weeds just watching. They went back to
the drawing boards, and the Tonka Trucks like the Little Hustler
disappeared, and VERY HIGH QUALITY autos came on the market. They are still
here. Just the way it is, I guess.
Jim Hupy
Salem, Oregon

On Fri, May 29, 2020, 11:03 AM tom geiger via Gmclist <

> How funny Jim H. The car I mention I got the Dot 5 suggest on their forum
> was a Triumph TR6. The brakes are the last item from the winter list I had
> to do. And of course they are giving me the most trouble. Once I get it
> flushed then I’ll be ready to drop it back on its feet again.
> Dot 3 is what I decided to go with so I think I’m close with that. Too
> funny on the Lockheed reference too. Had work with them for a extended
> period at the engineering firm I worked at. Small world kinda.
>
> Tom
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>
 
There's a reason the Brits drink warm beer, Lucas refrigerators :lol: :lol:

--
1977 Royale 101348,

1977 Royale 101586, Diesel powered,

1975 Eleganza II, 101230,

1974 Eagle Bus 45',w/slideout,

Rio Rancho, NM
 
I used Dot 5 in all my road race motorcycles....key word "race"....all fluids changed every week after a weekend of racing.
RV or Motorhome .... slow and leisurely.... all fluids changed maybe once a year therefore DOT 3/4/5.1.

Race bike = trailer full of spares....lots of DOT 5 in the cabinet.
Motorhome = Gas stations, Walmarts, truck stops etc.....not a common place to find DOT 5 fluid.

If you still want to run DOT 5 you better have enough in your RV as spare if something goes wrong and be willing to change it ALOT.
Biggest everyday bonus with Dot 5...wont strip your paint if you spill some on it :d
--
Rich Mondor,

Brockville, ON

77 Hughes 2600
 
You ever come south and run Road Atlanta?

--johnny
--
Foolish Carriage, 76 26' Eleganza(?) with beaucoup mods and add - ons.
Braselton, Ga.
I forgive them all, save those who hurt the dogs. They must answer to me in hell
 
Use to before i retired from racing a while back.....crashing just hurts to much when you get older...lol.

> You ever come south and run Road Atlanta?
>
> --johnny

--
Rich Mondor,

Brockville, ON

77 Hughes 2600
 
Rich, did you ever race at Mosport or Shannonville ?@?
I pwas in the first ever car race at Shannonville when John Nelson owned it.
I we end up having a car race at Shannonville this year I'll let you know. I'm the
Regional Chief of Scrutieering for CASC.
--
DAVE KING
lurker, wannabe
Toronto, Ontario, Canada
 
Being a Journeyman Small Engine Mechanic via apprenticeship, I had a big
interest in high performance small engines. Everything from hot rod
chainsaw competitions, and very, very fast outboard hydroplanes, racing
motorcycles, ( like the Mike Hailwood 6 cylinder 250 cc.and 350 cc Hondas.
Wow, dual overhead cam, 4 valves per cylinder, 6 carbs, waaaaay over square
engines that came on the cams about 17,500 rpms, and redlined at 23,500
rpms. Those things sounded like banshees screaming at full song. God, those
things were beyond scary fast.
Lastly, came go-carts. Both 4 cycle and 2 cycle. Imagine, if you will, an
engine that had the displacement of 2 salt shakers. (100 cc.) that produced
over 40 horsepower. Put that engine, or two of them on a competition
tubular frame that weighed less than 100 pounds. Add a 130 pound fearless
rider/driver, and you have a combination capable of well over 100 mph. In
fact, on the short course at Portland International Raceway, the single lap
record is quicker by a go-cart, than a D production Corvette. I used to be
stupid enough to race those carts. But, I gave away too much height and
weight to be truly competitive. I was a much better race mechanic, and
could tweak every bit of hidden horsepower out of those things. Lots of
fun, and memories too. If anyone remembers the Sneva's from Eastern
Washington state, Indy car champions, they started out with go carts. They
were awesome fast.
Jim Hupy
Salem, Oregon

On Sun, May 31, 2020, 6:43 PM Dave King via Gmclist
wrote:

> Rich, did you ever race at Mosport or Shannonville ?@?
> I pwas in the first ever car race at Shannonville when John Nelson owned
> it.
> I we end up having a car race at Shannonville this year I'll let you know.
> I'm the
> Regional Chief of Scrutieering for CASC.
> --
> DAVE KING
> lurker, wannabe
> Toronto, Ontario, Canada
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>
 
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