P32 sticking rear caliper

[jspringator]

I drove my 2002 Winnebago Sightseer 27c P32 for the first time in a couple of months. I had to a little bit aggresively apply the brakes at a light. When I started up again, the engine labored more than usual. When I parked, I noticed the smell of brake material. After it cooled a while, I applied the brakes and they went to the floor and the brake light came on. I waited about 45 minutes and tried again. The light was on, but when I pushed the pedal ALL the way down the brake light went off and stayed off. It is possible that there was some brake fluid where the driver's rear had been. There is an unexplained stain that hasn't evaperated.

In any event, after pumping the brakes they appear better than they were before, Before I hit a spot that was very hard to push through. Now, the brakes are easier to apply and appear to have more pedal. I'm not naive enough to believe they have healed.

My hypothesis is bad brake hose that somehow temporarily straightened cleared out. I'm sure round 2 is coming, and I'm leaving Wednesday for a 5 day trip where I will be moving most of the time.

There is no way to inspect the brake hose, so I probably need to get them anyway.

Any ideas? It is the brake fluid part that has me concerned. I'm taking it to a mechanic on Monday, but I want to have an idea of the problem before I take it.

[rgatijnet1]

Most hydraulic shops can make new hoses for you. Just take the old ones to them and they can duplicate them using newer and better materials.

[jspringator]

Mechanic couldn't find anything wrong. I did fill up the hydroboost resevoir that was on cold fill when hot. He thinks that caused it. I think it is the hoses. I'm going to replace them when I get back.

Where can I order a set of aftermarket brake hoses? He says he can't get them. I checked an Autozone and I know they can't order them.

[Stim]

I have had 2 motor homes on Chevy chassis, 83 Winnie and 89 Southwind.
I had problems with brake hoses on both.
The hose fails internally and acts as a check valve and won't let caliper release.
When yours was sticking it overheated the brake fluid and caused your problem.
Once it cooled off and you pumped the peddle back up the pressures came up and canceled the brake warning light.
The hoses should be available over the counter at most parts stores but you need to match them up with old when buying because the bracket for bolting might be different.

[jspringator]

Dropped it off at the mechanic this am.

Based on the loss of Brake fluid in the driver's rear I'm guessing bad leaking caliper. Doubt it is the hose because it did pump up.

I'll post up the result tomorrow when I get the verdict. I'm leaving on Wednesday so I won't have time for a full service.

[Passin_Thru]

Parker hose stores will make any hose you can dream up. Can't say where yours would be.

[Jim]

Sounds like a bad master cylinder to me since I had the same symptoms with my '94 Bounder with Freightliner chassis. Not that hard to replace. But following Brett's (wolfe10) advice is always a good way to go.

[wolfe10]

rgatijnet1 wrote:
One is to completely FLUSH the brake fluid every two years. This is not bleeding the brake system. This means running almost three quarts of brake fluid through your system to completely change the fluid.
The second thing that needs to be done is that the caliper brake disc slides need to be lubricated so that the calipers slide freely. If this is done every two years, your brakes will be fine for years to come.
Think of it as cheap insurance for your own safety and piece of mind.

I like your wording better than mine-- "complete bleed" is not as descriptive as FLUSH. We do the same thing, but yours is the better description.

And for any brake system with SLIDING CALIPERS (as opposed to fixed calipers) the clean and lube caliper slides is very important.

This is NOT just on gasoline rigs!

Our 1998 Safari Sahara DP had sliding caliper hydraulic brakes, requiring disassembly and greasing with caliper slide grease.

Our 2003 Alpine had fixed caliper hydraulic brakes, so this procedure not needed (or even possible).

And, yes, sliding caliper air disk brakes (like on Foretravel) require the same inspection, cleaning and lubing of caliper slide pins.

Now, for the best way to FLUSH hydraulic brakes:

Suck all fluid from the brake master cylinder or reservoir.
Fill with new fluid. Stir with clean screwdriver, etc.
Suck out fluid. Repeat until fluid is CLEAR. You do NOT want to run dirty/hydrated brake fluid through the system.

Go to the right rear wheel (furthest from master cylinder). Suck out fluid while someone is adding new fluid to master cylinder/reservoir until clear, clean fluid comes out.

Do the same at the left rear, then right front, then left front.

Verify that fluid level in the master cylinder/reservoir is correct.

REPEAT EVERY 2-3 YEARS.

[rgatijnet1]

You have two things that MUST be taken care of on a regular basis. One is to completely FLUSH the brake fluid every two years. This is not bleeding the brake system. This means running almost three quarts of brake fluid through your system to completely change the fluid.
The second thing that needs to be done is that the caliper brake disc slides need to be lubricated so that the calipers slide freely. If this is done every two years, your brakes will be fine for years to come.
Think of it as cheap insurance for your own safety and piece of mind.

[jspringator]

Within 2 years.

Where can I get the hoses?

[wolfe10]

Get new hoses and complete bleed of the brake system. Sounds like hydrated brake fluid as well as the pads not retracting. How old is the brake fluid?

[MountainAir05]

If your are taking this rv on the trip, I would fix it now not on the trip where you will most likely have to wait for the parts and maybe a tow in the middle of no where. At that age, if you have not done so the hoses and bleed the fluid, fix the leak or replace the leaking part.