Need Transmission Advice & Help

7

78gmcroyale

New member
Apr 2, 2015
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Good Evening

When I took the coach out of winter storage this week and got it home I discovered milky pinkish Fluid in the transmission. The coach performed fine
on the 30 mile trip home.

The current setup was the transmission fluid went to the radiator and then through an auxiliary cooler. Today I bypassed the radiator and went
directly through the cooler which has ample capacity to do the cooling.

Question I have is; what's the best way to flush the bad fluid out of the transmission?

All help and advice is appreciated.

Thanks

Ray

--
Ray Erspamer
78 GMC Royale Center Kitchen
403, 3.70 Final Drive
Holley Sniper Quadrajet EFI System,
Holley Hyperspark Ignition System
414-484-9431
 
Oh Ray....Holy $h1t!! Final drive, engine, now trans? GAHHHHHHHHH!!!

Well, seems like you diagnosed it right. Coolant in the trans fluid and got there through the cooler in the radiator.

Sooooooo.....

This is a very messy procedure; you're gonna spill fluid, so be prepared
with dry rags and the like to clean-up afterwards.

I'd do this procedure twice. The first time with cheap fluid from Walmart. After the procedure, take it for a 10 mile easy drive. Then look at the
fluid. If there is still a lot of pinkish stuff, do it again with cheap fluid. If it looks normal, then put in your choice of fluid and drive it.
Watch it on second or third change and maybe take a sample and send to Blackstone Labs for analysis.

1. Do this with the trans cold. Wait at least over night.
2. Raise the coach high enough to get a 5 gal pail under it with room to
spare.
3. Disconnect both trans lines at the radiator, and be prepared to catch the
fluid coming out of the cooler in the radiator.
4. Attach hose extensions to the lines and drop the lines into the 5 gal
pail.
5. Using two people, start the motor for only couple of seconds. Do this to
identify which line the fluid will come out of. Now you know which line you
*must* keep in the bucket.
6. Again, using two people, (one to run the motor, the other to watch the
fluid) start the motor.
7. Run the motor until the fluid line begins spurting air. Shut motor off
immediately! The fluid will get quite frothy.
8. Allow to stand without the motor running for 4-5 minutes. This will let
excess fluid in the trans drain down into the pan.
9. Start the motor again for no more than 5 seconds. Shut off the motor.
This will pump out that last little bit in the pan and make dropping the pan
a lot less messy.
10. Let the oil lines drip into the pail while you drop the trans pan.
11. Drop the trans pan, and replace the filter using two (2) "O" rings at
the filter.
12. Hook up the two trans lines to the oil cooler at the radiator.
13. Fill the trans with about 7 quarts of trans fluid.
14. Start the motor and allow to idle for about 30 seconds or so before
checking fluid level.
15. Check fluid level and add accordingly.
16. Once full, drive until normal operating temp is reached, and recheck
fluid level. Add fluid to bring to "Full".

Personally, I'd use Mobile 1 as my final fill.

I've used this procedure on every auto trans that I've owned for .... well
.... forever.

This is just the way I do it....your mileage may vary.

BTW, How's the 455 doing?

--
Larry
78 Royale w/500 Caddy
Menomonie, WI.
 
Thanks Larry, I appreciate it.=C2=A0 This transmission was rebuilt by Steve=
Turnquist years ago.The 403 is running fine...knock on wood.=C2=A0 I'll ke=
ep you posted on the flush.Ray.Sent from my U.S.Cellular=C2=A9 Smartphone=
-------- Original message --------From: Larry Date: 3=
/25/21 9:02 PM (GMT-06:00) To: gmclist Subject: [GMCnet] =
Re: Need Transmission Advice & Help Oh Ray....Holy $h1t!! Final drive, engi=
ne, now trans? GAHHHHHHHHH!!!Well, seems like you diagnosed it right. Coola=
nt in the trans fluid and got there through the cooler in the radiator. Soo=
ooooo.....This is a very messy procedure; you're gonna spill fluid, so be p=
reparedwith dry rags and the like to clean-up afterwards.I'd do this proced=
ure twice. The first time with cheap fluid from Walmart. After the procedur=
e, take it for a 10 mile easy drive. Then look at thefluid. If there is sti=
ll a lot of pinkish stuff, do it again with cheap fluid. If it looks normal=
, then put in your choice of fluid and drive it.Watch it on second or third=
change and maybe take a sample and send to Blackstone Labs for analysis.1.=
Do this with the trans cold. Wait at least over night.2. Raise the coach h=
igh enough to get a 5 gal pail under it with room tospare.3. Disconnect bot=
h trans lines at the radiator, and be prepared to catch thefluid coming out=
of the cooler in the radiator.4. Attach hose extensions to the lines and d=
rop the lines into the 5 galpail.5. Using two people, start the motor for o=
nly couple of seconds. Do this toidentify which line the fluid will come ou=
t of. Now you know which line you*must* keep in the bucket.6. Again, using =
two people, (one to run the motor, the other to watch thefluid) start the m=
otor.7. Run the motor until the fluid line begins spurting air. Shut motor =
offimmediately! The fluid will get quite frothy.8. Allow to stand without t=
he motor running for 4-5 minutes. This will letexcess fluid in the trans dr=
ain down into the pan.9. Start the motor again for no more than 5 seconds. =
Shut off the motor.This will pump out that last little bit in the pan and m=
ake dropping the pana lot less messy.10. Let the oil lines drip into the pa=
il while you drop the trans pan.11. Drop the trans pan, and replace the fil=
ter using two (2) "O" rings atthe filter.12. Hook up the two trans lines to=
the oil cooler at the radiator.13. Fill the trans with about 7 quarts of t=
rans fluid.14. Start the motor and allow to idle for about 30 seconds or so=
beforechecking fluid level.15. Check fluid level and add accordingly.16. O=
nce full, drive until normal operating temp is reached, and recheckfluid le=
vel. Add fluid to bring to "Full". Personally, I'd use Mobile 1 as my final=
fill.I've used this procedure on every auto trans that I've owned for ....=
well.... forever.This is just the way I do it....your mileage may vary.BTW=
, How's the 455 doing?-- Larry=C2=A0 78 Royale w/500 CaddyMenomonie, WI.___=
____________________________________________GMCnet mailing listUnsubscribe =
or Change List Options:
 
Might suggest you find the leak before you put in fresh fluid. Probably mea=
ns pulling the radiator. HTH Sent from my iPhone Nelson Wright=
78 Royal rear bath Orlando Fl. > On Mar 25, 2021, at 10:12 PM, 78=
gmcroyale wrote: > > =EF=BB=BFThanks Larry, I =
appreciate it. This transmission was rebuilt by Steve Turnquist years ago.=
The 403 is running fine...knock on wood. I'll keep you posted on the flush=
.Ray.Sent from my U.S.Cellular=C2=A9 Smartphone > -------- Original mess=
age --------From: Larry Date: 3/25/21 9:02 PM (GMT-06:=
00) To: gmclist Subject: [GMCnet] Re: Need Transmission Adv=
ice & Help Oh Ray....Holy $h1t!! Final drive, engine, now trans? GAHHHHHHHH=
H!!!Well, seems like you diagnosed it right. Coolant in the trans fluid and=
got there through the cooler in the radiator. Sooooooo.....This is a very =
messy procedure; you're gonna spill fluid, so be preparedwith dry rags and =
the like to clean-up afterwards.I'd do this procedure twice. The first time=
with cheap fluid from Walmart. After the procedure, take it for a 10 mile =
easy drive. Then look at thefluid. If there is still a lot of pinkish stuff=
, do it again with cheap fluid. If it looks normal, then put in your choice=
of fluid and drive it.Watch it on second or third change and maybe take a =
sample and send to Blackstone Labs for analysis.1. Do this with the trans c=
old. Wait at least over night.2. Raise the coach high enough to get a 5 gal=
pail under it with room tospare.3. Disconnect both trans lines at the radi=
ator, and be prepared to catch thefluid coming out of the cooler in the rad=
iator.4. Attach hose extensions to the lines and drop the lines into the 5 =
galpail.5. Using two people, start the motor for only couple of seconds. Do=
this toidentify which line the fluid will come out of. Now you know which =
line you*must* keep in the bucket.6. Again, using two people, (one to run t=
he motor, the other to watch thefluid) start the motor.7. Run the motor unt=
il the fluid line begins spurting air. Shut motor offimmediately! The fluid=
will get quite frothy.8. Allow to stand without the motor running for 4-5 =
minutes. This will letexcess fluid in the trans drain down into the pan.9. =
Start the motor again for no more than 5 seconds. Shut off the motor.This w=
ill pump out that last little bit in the pan and make dropping the pana lot=
less messy.10. Let the oil lines drip into the pail while you drop the tra=
ns pan.11. Drop the trans pan, and replace the filter using two (2) "O" rin=
gs atthe filter.12. Hook up the two trans lines to the oil cooler at the ra=
diator.13. Fill the trans with about 7 quarts of trans fluid.14. Start the =
motor and allow to idle for about 30 seconds or so beforechecking fluid lev=
el.15. Check fluid level and add accordingly.16. Once full, drive until nor=
mal operating temp is reached, and recheckfluid level. Add fluid to bring t=
o "Full". Personally, I'd use Mobile 1 as my final fill.I've used this proc=
edure on every auto trans that I've owned for .... well.... forever.This is=
just the way I do it....your mileage may vary.BTW, How's the 455 doing?-- =
Larry 78 Royale w/500 CaddyMenomonie, WI._________________________________=
______________GMCnet mailing listUnsubscribe or Change List Options: > __=
_____________________________________________ > GMCnet mailing list > U=
nsubscribe or Change List Options:
 
Nelson is correct, by pass the cooler first and then get12 gallon of fluid
and do the flush.
Call me if you need the procedure or others can wright it to you.

> Might suggest you find the leak before you put in fresh fluid. Probably
> means pulling the radiator.
> HTH
>
>
> Sent from my iPhone
> Nelson Wright
> 78 Royal rear bath
> Orlando Fl.
>

> >
> > Thanks Larry, I appreciate it. This transmission was rebuilt by Steve
> Turnquist years ago.The 403 is running fine...knock on wood. I'll keep you
> posted on the flush.Ray.Sent from my U.S.Cellular© Smartphone
> > -------- Original message --------From: Larry Date:
> 3/25/21 9:02 PM (GMT-06:00) To: gmclist Subject:
> [GMCnet] Re: Need Transmission Advice & Help Oh Ray....Holy $h1t!! Final
> drive, engine, now trans? GAHHHHHHHHH!!!Well, seems like you diagnosed it
> right. Coolant in the trans fluid and got there through the cooler in the
> radiator. Sooooooo.....This is a very messy procedure; you're gonna spill
> fluid, so be preparedwith dry rags and the like to clean-up afterwards.I'd
> do this procedure twice. The first time with cheap fluid from Walmart.
> After the procedure, take it for a 10 mile easy drive. Then look at
> thefluid. If there is still a lot of pinkish stuff, do it again with cheap
> fluid. If it looks normal, then put in your choice of fluid and drive
> it.Watch it on second or third change and maybe take a sample and send to
> Blackstone Labs for analysis.1. Do this with the trans cold. Wait at least
> over night.2. Raise the coach high enough to get a 5 gal pail under it with
> room tospare.3. Disconnect both trans lines at the radiator, and be
> prepared to catch thefluid coming out of the cooler in the radiator.4.
> Attach hose extensions to the lines and drop the lines into the 5
> galpail.5. Using two people, start the motor for only couple of seconds. Do
> this toidentify which line the fluid will come out of. Now you know which
> line you*must* keep in the bucket.6. Again, using two people, (one to run
> the motor, the other to watch thefluid) start the motor.7. Run the motor
> until the fluid line begins spurting air. Shut motor offimmediately! The
> fluid will get quite frothy.8. Allow to stand without the motor running for
> 4-5 minutes. This will letexcess fluid in the trans drain down into the
> pan.9. Start the motor again for no more than 5 seconds. Shut off the
> motor.This will pump out that last little bit in the pan and make dropping
> the pana lot less messy.10. Let the oil lines drip into the pail while you
> drop the trans pan.11. Drop the trans pan, and replace the filter using two
> (2) "O" rings atthe filter.12. Hook up the two trans lines to the oil
> cooler at the radiator.13. Fill the trans with about 7 quarts of trans
> fluid.14. Start the motor and allow to idle for about 30 seconds or so
> beforechecking fluid level.15. Check fluid level and add accordingly.16.
> Once full, drive until normal operating temp is reached, and recheckfluid
> level. Add fluid to bring to "Full". Personally, I'd use Mobile 1 as my
> final fill.I've used this procedure on every auto trans that I've owned for
> .... well.... forever.This is just the way I do it....your mileage may
> vary.BTW, How's the 455 doing?-- Larry 78 Royale w/500 CaddyMenomonie,
> WI._______________________________________________GMCnet mailing
> listUnsubscribe or Change List Options:
> > _______________________________________________
> > GMCnet mailing list
> > Unsubscribe or Change List Options:
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
>

--
Jim Kanomata
Applied/GMC, Newark,CA
jimk
http://www.gmcrvparts.com
1-800-752-7502
 
Ya, if coolant was leaking into the trans cooler, it is a good bet trans fluid could have leaked into the coolant. Best check the radiator for red
stuff. Sounds like you have bypassed the radiator already?
--
Larry
78 Royale w/500 Caddy
Menomonie, WI.
 
If you bypass the trans cooler in the radiator, be sure to plug the fittings as leaks are usually bidirectional.
--
John Lebetski
Woodstock, IL
77 Eleganza II
 
That was my plan John.  But thanks for the reminder.Sent from my U.S.Cellular© Smartphone
-------- Original message --------From: "John R. Lebetski" Date: 3/26/21 9:36 AM (GMT-06:00) To: gmclist Subject: [GMCnet] Re: Need Transmission Advice & Help If you bypass the trans cooler in the radiator, be sure to plug the fittings as leaks are usually bidirectional. -- John LebetskiWoodstock, IL77 Eleganza II_______________________________________________GMCnet mailing listUnsubscribe or Change List Options:
 
I just finished bypassing the radiator transmission cooler. Doesn't look like any transmission fluid got into the coolant.

I've sent in a sample of the transmission fluid to Blackstone for analysis.
--
Ray Erspamer
78 GMC Royale Center Kitchen
403, 3.70 Final Drive
Holley Sniper Quadrajet EFI System,
Holley Hyperspark Ignition System
414-484-9431
 
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