Brake Problems 1983 Holiday Rambler Chevy P30 Chassis

TripleJ · January 06, 2016, 08:22 PM

Hotdawg before it comes apart again, look to the symptoms. You did say it was now drivable and stops on demand. Does that mean with the shim installed, the brakes did NOT seize up like before?

You stated that the brakes were still getting hot, we know that they actually SHOULD be hot. Too hot to touch even. SMOKING is too hot, SEIZING is too hot obviously...

You stated that the engine was lugging, but it is not clear that is due to the brakes dragging. After driving for a mile or two and coming to a stop, can you lift off the brake pedal? Does the vehicle begin to roll or does it stay planted/stuck?

Last, the pedal is too far down, you stated 1/2 way before the brakes begin to apply. I can tell you that my 85 has a long pedal, maybe 1/2, maybe a little higher. The only thing I would do it do a round of brake bleeding, but like I said, as long as they will lock up from where they are, I say they are ok.

If you could clarify these things...

Hotdawg22 · January 08, 2016, 09:58 AM

Hello all. Wonderful suggestions and leads here and i appreciate it all. When you replace multiple items and later discover you have a problem associated with that system, it is hard to locate the offender. In my case it could be any one of the components.
Good news first. Tackled the water leak which i thought was the water pump and turned out it was the bottom radiator hose on the pump. The clamp was just loose enough to let water out and it was running down the water pump and looked like the fromt seal on the pump. The clamp was a bit hard to get to because of the way i installed the clamp but i fixed it.
After i installed the shims on the MC i had no lockups afterwards. SO maybe the heat i was feeling from the rotors was normal, as TripleJ was suggesting. The brakes as they are now will stop the MH very well. The pedal does go down about half way but the brakes are very good and stops quickly. I will do the test drive and see if it will move on its own from a start at idle.
I have read the suggestions and was interested in the supposition that the brake rotors will get hot from normal driving and stopping. Maybe i don't have a problem as i thought. Guess i am a little gun shy because of the lockups i have had on it. I don't think the rotors or pads were actually damaged by the lockups and they all appear to be normal color, no blue in the rotors etc. The only time they actually smoked was the first time and because they locked up and actually stopped the vehicle they were not hot for long. Also, the smoke was probably from debris and grease on them from rebuilding and setting for 5 years.
So with that in mind i have decided to leave it all as is for the time being and am going for a long test drive this weekend to see what will happen.

Rickf1985 · January 08, 2016, 10:54 AM

Another thing to consider with the smoke from the brakes, and this only pertains IF they were not actually locked. On better quality pads they apply a break in coating on the pad which helps mate the rotor with the pad. You are supposed to test drive it and make a few easy stops before hammering on it. This coating will smoke and grab if you do not do the break in properly. From what you were saying the tag axle was doing the same thing and that is on a separate system from the Hydroboost so do not rule out a bad master cylinder yet. On normal driving the brakes will get hot but you should not feel excessive heat. If you put the back of your hand next to the wheel after a normal easy stop and take a normal amount of time to get out and check you should not feel any heat radiating out from the brakes. If it is hot enough to feel it on the back of your hand from the outside of the wheel then there is something wrong. Be sure to do the check where you just drop it in gear without touching the brake and see if it moves and then pop it in neutral, again no brake and see if it rolls of stops like the brakes are on. Disc brakes are always touching but not enough that you will notice it in any checks like that. If you jack the wheel up you can spin it by hand, that is how little they touch.

Hotdawg22 · January 12, 2016, 04:09 PM

OK all, i just got back from the practice run and am pleased to announce that the problem has been solved.
I did the "roll to a stop" test and the rotors were OK, no heat to speak of.
I did "let it idle on level ground" to see if it would move and it did with no problem. If i let up on the brake at any stop along the way it moved on its own, even in reverse.
I did a stop or 2 and checked the rotors and the heat was not excessive. I compared what i felt to my Dodge dually and they were about the same.
So i am good to go.Thanks for all the help on this Forum: YOU ALL THE BEST:)

jeno · January 12, 2016, 04:23 PM

What was the one thing that caused the problem?

Rickf1985 · January 12, 2016, 05:04 PM

You might want to remove those washers that you put in for spacers, that is not a real good fix since it will let contaminates into the back of the booster. If the problem happens again you know what it is, just make a full contact spacer out of thick gasket material. If you lost half a pedal with the washers then you would only need half of that if anything at all.

Hotdawg22 · January 12, 2016, 05:57 PM

The overall problem was the distance between the master cylinder and the hydrobooster. Apparently when they rebuilt one or the other the clearance was not the same as my old system. Recall the pushrod between the two is fixed and not adjustable.
So, in reality what solved the problem was inserting a split washer on each bolt that holds the MC onto the booster. Those washers were about 50 thousands thick. I never would have believed it had i not seen it.
Anyway, now i will find or make a metal gasket the same thickness as the washers and put that gasket in place of the washers. That, like Rick says, will seal the two back up to keep road grit out.
And, because of the way it is all put together, i will have to take all the lines loose and completly remove the MC in order to get the gasket on.
At least the end is near. LOL

Rickf1985 · January 12, 2016, 06:44 PM

I think that is way too much spacer, I would think half of that is more than enough.

jeno · January 12, 2016, 07:18 PM

Froggy1936 · January 12, 2016, 09:07 PM

If you are going to remove the master cly Why not just shorten the rod 1/2 the thickness of the washers ? This could be done with a grinder or a dremmel with a cut off disk (tape the opening of the booster to keep out grindings )

Also first check inside Master cly piston for a foreign object That would take up space ! Frank

Rickf1985 · January 12, 2016, 09:53 PM

I wouldn't cut the rod because if you have to replace the stuff again you may need the original length. This stuff is going to start to be hard to come by and it is easier to shim the two apart than it is to weld that rod back to the right length. That said, you want the pedal as high as possible so that if you have to make a panic stop and really stand on the brakes you will not run out of pedal as the hoses expand under the extra pressure.

Adventure Seeker · May 11, 2016, 10:36 PM

Hello,

I am new to forum looking for direction. Hotdawg22 who did you have rebuild the tag axel brake system in Houston? I have an 84 Holiday Rambler Presidential with a 6.9 Ford diesel on a Ford chassis with the tag axel brakes inop. I tried myself to get the rear system in order. I added fluid to the master cylinder on the tag system, had the motor running, and tried to bleed the system but was unsuccessful. I then opted to take it to a mechanic that specializes in these system. He spent 1 hr. on it and told me no go. I then looked into electric over hydraulic system and was told that it will not work with this system from the same mechanic. I know the mechanic, so I know he's not spinning me, but I know there is always another way. If anyone can advise me that would be great. I was directed to Precision Heavy Duty in Mo. for rebuild and also Bludot for vacuum. Any direction from anyone would be great. Also I think Morryde is out of business

M & J · May 11, 2016, 10:44 PM

I've only seen 1 other class C with a tag axle.

Adventure Seeker · May 11, 2016, 10:53 PM

Thanks, the best part is the 6.9 diesel. When I got it years back it had 56,000 original miles. It was mint and I spent 3900.00 on it. It doesn't move fast but I get almost 15mpg fully loaded with everything you see hanging on it. Going up hills it smokes like mad but it has climbed all of the highest passes in the US and it always starts. Always!

DaveVA78Chieftain · May 12, 2016, 08:35 PM

Have you read this? http://www.classicwinnebagos.com/forum/index.php/topic,9132.0.html

Adventure Seeker · May 15, 2016, 09:58 PM

Yes, outstanding info. I spoke to Tim at Precision Rebuilders in Missouri. He will rebuild everything for the tag system for 400.00. I am getting fluid to the syncro bleeder and also the final bleeder on the rear master cyl going back to the tag but I cant get brake fluid out the rear of the master cyl to the tag. I pulled the brake line to the rear tag and no fluid. I had it running trying to bleed. I replaced a 1/2 rubber hose from the air pump to the booster on the tag but still nothing. Is there a difference in how this operates bc this is a diesel or do you have a general idea on how to bleed this system. I may not even need the equipment rebuilt, I may just be bleeding something wrong. Any thoughts
?

legomybago · May 16, 2016, 10:14 AM

I wonder if your system has anything to do with the vacuum pump on the 6.9 being bad or weak? Does your climate control still switch from defrost to vent etc..? How does the power brakes feel? Some ideas...

Rickf1985 · May 16, 2016, 10:17 AM

Is your vacuum pump on the engine working? If you have no vacuum going to the booster then you will have no assist. The "air" is just a filtered breather.

Adventure Seeker · May 16, 2016, 10:37 AM

Yes the vacuum pump is working but I am not sure if its weak. I will try the adjustments on defrost. The power brakes are weak but I think that's because when I replaced the whole brake system I did not bench bleed the master cyl. I have brought this to 2 different beyond competent shops and nobody knows about the second system. I think I am going to send the system to Precision to have it rebuilt and go from there. Do either of you have any idea on how to bleed that system? Any info would be great!

Rickf1985 · May 16, 2016, 02:08 PM

I am not at all familiar with that system, I just saw the vacuum on the diagram and I know those pumps do fail. Get a gauge and make sure you are getting at least 22-23 inches of vacuum.

DaveVA78Chieftain · May 16, 2016, 07:02 PM

Any feedback I can give is going to be based on this configuration from the Tag Axle thread. If your setup is dfferent in some way you need to explain that.

P30 with Tag axle brake bleeding: http://www.classicwinnebagos.com/forum/index.php?topic=9167.0

MorRyde is still in business. CWVRV member ClydesdaleKevin has been to their shop within the last year or so.

Since the Tag Booster Operation depends on vacuum (no hydraulic valve operation), make sure you do not have any vacuum leaks.

At rest, there is vacuum on both sides of the Tag Axle Booster diaphram. When you depess the brakes, the Synchronyzer valve ports outside air to one side of the booster. With vacuum pulling on one side of the diaphram and outside air pushing on the other side of the diapharam, the attached rod pushes on the tag axle MC applying the tag axle brakes. So, one must check for operation of sychronyzer then operation of the booster/MC.