Help and advice to new owners

[jtkthatcher]

We would greatly appreciate any advice/information on the following.

1. Our coach has 4 tires load rated E and 2 that are load rated D. The D
rated ties are on the tag axle and the E's on the front and other rear axle.
The D tires have a 65 # rating and the E tires have an 80 # rating. The
tire pressure recommended on the sticker in the glove box is 60 Does
anyone have some knowledge or advice on what pressure(s) we should use in
the D's and E's, and if this tire configuration is OK? If not what should
we do?

2. The former owner cautioned us that the engine had been tuned for 92-93
octane "only". The manuals make no reference to using a premium fuel. I
have read many of the recent E-Mails where it is suggested that 87 octane is
OK. Can someone offer us some advice?

3. We have our new coach in a secure covered storage location. We do not
plan to use it for the next 2 months. Is there anything special that we
should or should not do? Specifically, how should the rear air bag
suspension be set?

4. Our cruise control does not work. A person with "some" knowledge has
examined this and indicates that some of the pieces are missing. We want
cruise control. Do you recommend that we attempt to repair the original or
to have an aftermarket unit installed. If repair is suggested, where might
the missing pieces be available?

5. The dash air is puting out somewhat cool air, however not at all cool
enough to be effective. A manual valve exists that stops the circulation of
the radiator water while cooling. The valve is functioning (I think). If we
turn the compressor off, the air coming out is very warm/hot. Anyone have
any thoughts?

Thank you in advance

Judy and Ken Thatcher

 

[patrick flowers]

>
> We would greatly appreciate any advice/information on the following.
>
> 1. Our coach has 4 tires load rated E and 2 that are load rated D.
> The D rated ties are on the tag axle and the E's on the front and
> other rear axle. The D tires have a 65 # rating and the E tires have
> an 80 # rating. The tire pressure recommended on the sticker in the
> glove box is 60 Does anyone have some knowledge or advice on what
> pressure(s) we should use in the D's and E's, and if this tire
> configuration is OK? If not what should we do?

The GMC's originally came with D rated tires, but there were quite a few
failures so they switched to E rated tires. My father and I have both
had good experience with General 16.5 inch D rated tires. D rated tires
on the rear shouldn't be a problem. The Bridgestone tires web site,
www.trucktires.com(I think - Paul Bartz correct me if I'm wrong) has a
link to a tire pressure/load rating table that's very useful.

> 2. The former owner cautioned us that the engine had been tuned for
> 92-93 octane "only". The manuals make no reference to using a
> premium fuel. I have read many of the recent E-Mails where it is
> suggested that 87 octane is OK. Can someone offer us some advice?

Unless the engine's been rebuilt with a higher compression ratio than
stock, about the only difference would be timing. If all he did was
advance the distributor until it pinged and then backed off, you can
just reset the distributor to the stock timing. If the distributor was
recurved, you'll need to have it recurved back. Get more details from
the PO. There's a GMC dealer on the net that rebuilds and recurves
distributors specifically for the motorhomes. I don't recall the URL,
but I'm sure Paul Bartz has it. It's also in the archives.

> 3. We have our new coach in a secure covered storage location. We
> do not plan to use it for the next 2 months. Is there anything
> special that we should or should not do? Specifically, how should
> the rear air bag suspension be set?

Some people recommend "squatting" the rear end when parked to increase
the life of the air bags. I'm not sure it makes that much of a
difference. Two months is not a very long storage period. You might
want to set some rat bait stations around the wheels to prevent furry
neighbors from moving in.

> 4. Our cruise control does not work. A person with "some" knowledge
> has examined this and indicates that some of the pieces are missing.
> We want cruise control. Do you recommend that we attempt to repair
> the original or to have an aftermarket unit installed. If repair is
> suggested, where might the missing pieces be available?

The factory cruise is very simple and the wiring diagram is included in
the service manual(if you haven't ordered one from Cinnabar, you need
to). The major components are the transducer which is mounted on the
rear of the engine compartment just under the cover and the servo which
is a vacuum motor mounted behind the air cleaner. The parts are readily
available and there have been several listed in previous posts(check the
archives).

> 5. The dash air is puting out somewhat cool air, however not at all
> cool enough to be effective. A manual valve exists that stops the
> circulation of the radiator water while cooling. The valve is
> functioning (I think). If we turn the compressor off, the air coming
> out is very warm/hot. Anyone have any thoughts?

I've yet to tackle this one on my coach, but there's plenty to go wrong
here. Start with the maintenance manual and go through the
diagnostics. Check for broken cables, bad vacuum lines and "vanished"
air valve seals. Tracking these gremlins down is part of the "fun" of
owning a GMC.

Patrick
- --
Patrick Flowers
Mailtoatri63

The GMC Motorhome Page
http://www.gmcmotorhome.com

 

[bartz paul]

J & K Thatcher:

When you open the tire web site, click on the Bridgestone bar in the top
right corner and then click on Load/Inflation Tables item.

The distributor web site is http://paterson-gmc.com/~gmc/motorhome.html
and then click on the underlined item in red titled Springfield
Ignition.

On your dash A/C. You say it's "very warm/hot" with the A/C off.
That's not at all indicative of the valve in the coolant hoses to the
heater core being in the cut-off/closed position. Does the valve have a
rectangular handle that swings about 90 degrees from one limit to the
opposite limit? If so, it's a ball valve and they usually are very
reliable. Try swinging the valve handle the opposite way a see if it
makes a difference in the air discharge temperature while going down the
road.

Paul Bartz

From: Patrick Flowers [mailtoatri63]
Sent: Friday, August 07, 1998 1:25 PM
Subject: Re: GMC: Help and advice to new owners

We would greatly appreciate any advice/information on the following.

1. Our coach has 4 tires load rated E and 2 that are load rated D. The
D rated ties are on the tag axle and the E's on the front and other rear
axle. The D tires have a 65 # rating and the E tires have an 80 #
rating. The tire pressure recommended on the sticker in the glove box
is 60 Does anyone have some knowledge or advice on what pressure(s)
we should use in the D's and E's, and if this tire configuration is OK?
If not what should we do?

The GMC's originally came with D rated tires, but there were quite a few
failures so they switched to E rated tires. My father and I have both
had good experience with General 16.5 inch D rated tires. D rated tires
on the rear shouldn't be a problem. The Bridgestone tires web site,
www.trucktires.com I think - Paul Bartz correct me if I'm wrong) has a
link to a tire pressure/load rating table that's very useful.

2. The former owner cautioned us that the engine had been tuned for
92-93 octane "only". The manuals make no reference to using a premium
fuel. I have read many of the recent E-Mails where it is suggested that
87 octane is OK. Can someone offer us some advice?

Unless the engine's been rebuilt with a higher compression ratio than
stock, about the only difference would be timing. If all he did was
advance the distributor until it pinged and then backed off, you can
just reset the distributor to the stock timing. If the distributor was
recurved, you'll need to have it recurved back. Get more details from
the PO. There's a GMC dealer on the net that rebuilds and recurves
distributors specifically for the motorhomes. I don't recall the URL,
but I'm sure Paul Bartz has it. It's also in the archives.

3. We have our new coach in a secure covered storage location. We do
not plan to use it for the next 2 months. Is there anything special
that we should or should not do? Specifically, how should the rear air
bag suspension be set?

Some people recommend "squatting" the rear end when parked to increase
the life of the air bags. I'm not sure it makes that much of a
difference. Two months is not a very long storage period. You might
want to set some rat bait stations around the wheels to prevent furry
neighbors from moving in.

4. Our cruise control does not work. A person with "some" knowledge has
examined this and indicates that some of the pieces are missing. We
want cruise control. Do you recommend that we attempt to repair the
original or to have an aftermarket unit installed. If repair is
suggested, where might the missing pieces be available?

The factory cruise is very simple and the wiring diagram is included in
the service manual(if you haven't ordered one from Cinnabar, you need
to). The major components are the transducer which is mounted on the
rear of the engine compartment just under the cover and the servo which
is a vacuum motor mounted behind the air cleaner. The parts are readily
available and there have been several listed in previous posts(check the
archives).

5. The dash air is puting out somewhat cool air, however not at all
cool enough to be effective. A manual valve exists that stops the
circulation of the radiator water while cooling. The valve is
functioning (I think). If we turn the compressor off, the air coming
out is very warm/hot. Anyone have any thoughts?

I've yet to tackle this one on my coach, but there's plenty to go wrong
here. Start with the maintenance manual and go through the diagnostics.
Check for broken cables, bad vacuum lines and "vanished" air valve
seals. Tracking these gremlins down is part of the "fun" of owning a
GMC.

 

[thomas g. warner]

for distributors for the GMC its Dick Paterson at http://www.webgate.net/~gmc/

>>
>> We would greatly appreciate any advice/information on the following.
>>
>> 1. Our coach has 4 tires load rated E and 2 that are load rated D.
>> The D rated ties are on the tag axle and the E's on the front and
>> other rear axle. The D tires have a 65 # rating and the E tires have
>> an 80 # rating. The tire pressure recommended on the sticker in the
>> glove box is 60 Does anyone have some knowledge or advice on what
>> pressure(s) we should use in the D's and E's, and if this tire
>> configuration is OK? If not what should we do?
>
>The GMC's originally came with D rated tires, but there were quite a few
>failures so they switched to E rated tires. My father and I have both
>had good experience with General 16.5 inch D rated tires. D rated tires
>on the rear shouldn't be a problem. The Bridgestone tires web site,
>www.trucktires.com(I think - Paul Bartz correct me if I'm wrong) has a
>link to a tire pressure/load rating table that's very useful.
>
>> 2. The former owner cautioned us that the engine had been tuned for
>> 92-93 octane "only". The manuals make no reference to using a
>> premium fuel. I have read many of the recent E-Mails where it is
>> suggested that 87 octane is OK. Can someone offer us some advice?
>
>Unless the engine's been rebuilt with a higher compression ratio than
>stock, about the only difference would be timing. If all he did was
>advance the distributor until it pinged and then backed off, you can
>just reset the distributor to the stock timing. If the distributor was
>recurved, you'll need to have it recurved back. Get more details from
>the PO. There's a GMC dealer on the net that rebuilds and recurves
>distributors specifically for the motorhomes. I don't recall the URL,
>but I'm sure Paul Bartz has it. It's also in the archives.
>
>> 3. We have our new coach in a secure covered storage location. We
>> do not plan to use it for the next 2 months. Is there anything
>> special that we should or should not do? Specifically, how should
>> the rear air bag suspension be set?
>
>Some people recommend "squatting" the rear end when parked to increase
>the life of the air bags. I'm not sure it makes that much of a
>difference. Two months is not a very long storage period. You might
>want to set some rat bait stations around the wheels to prevent furry
>neighbors from moving in.
>
>> 4. Our cruise control does not work. A person with "some" knowledge
>> has examined this and indicates that some of the pieces are missing.
>> We want cruise control. Do you recommend that we attempt to repair
>> the original or to have an aftermarket unit installed. If repair is
>> suggested, where might the missing pieces be available?
>
>The factory cruise is very simple and the wiring diagram is included in
>the service manual(if you haven't ordered one from Cinnabar, you need
>to). The major components are the transducer which is mounted on the
>rear of the engine compartment just under the cover and the servo which
>is a vacuum motor mounted behind the air cleaner. The parts are readily
>available and there have been several listed in previous posts(check the
>archives).
>
>> 5. The dash air is puting out somewhat cool air, however not at all
>> cool enough to be effective. A manual valve exists that stops the
>> circulation of the radiator water while cooling. The valve is
>> functioning (I think). If we turn the compressor off, the air coming
>> out is very warm/hot. Anyone have any thoughts?
>
>I've yet to tackle this one on my coach, but there's plenty to go wrong
>here. Start with the maintenance manual and go through the
>diagnostics. Check for broken cables, bad vacuum lines and "vanished"
>air valve seals. Tracking these gremlins down is part of the "fun" of
>owning a GMC.
>
>Patrick
>--
>Patrick Flowers
>Mailtoatri63
>
>The GMC Motorhome Page
>http://www.gmcmotorhome.com
>
>