Brakes pull left

[outofcontrol]

1981 AS Excella 280 Motorhome, 454 chevy motor, P30 Chassis, 60k mi.

When I apply the brakes the coach pulls to the left. When I visually inspected the front end, I noticed several things wrong, so I decided to fix them all, and see if it corrected the problem.

1. The front swaybar bushings were ruptured/broken/old, and almost gone on the left side, so I replaced them.
2. The LF airbag leaked, so I replaced the set (what a PITA).
3. I thought it might be the shocks, so I replaced them (bilstiens).
4. The only thing left I see is a leak from the hydroboost to the brakes? I'm not real familiar...well I don't know anything about this system, except what I've read here--I do know not to tighten the belt using the pump body .

I'm not sure if a leak would make the brakes pull one direction?
I'm going to fix the leak anyway, but I'm going to need some help with ideas on where to look next.

Ball joints? Bleed the brake lines? Take it to a Mechanic? Something loose?

I have pulled the wheels off, and everything looks ok; the pads are good, the rotors look fine, there's no oil squirting on the rotors. I kind of expected to see something obvious.

It also seems like you have to put a lot of foot into the pedal to get the coach to stop. I drove trucks for 12 years (all air brakes) and the feel seems really heavy- granted I have nothing to compare it with.

My goal is to have the brakes work well enough to let my wife drive, and right now I wouldn't let anyone drive it. I've spent several hours reading posts here, but nothing specific about brakes pulling. What makes this happen?

Thanks in advance!! I've owned this RV for 3 weeks now, and I've spent 3 awesome weekends in it.

-Kevin

[wkerfoot]

OutofControl.

Could be a sticking caliper on the right side. Which is not engaging.

Bill

[scottanlily]

one of the most common troubles are the front brake hoses.Interestingly I am replacing a set for a customer with the same type chassis but sob .They close up from deterioration from the inside and then ,and usually one side more than the other does not release completely ,as the brakes are applied that calipar will grab more than the other,your trouble sounds like a calipar problem,one is most likely not applying very well while the other is clamping the rotor,you will get a pull to the side that is doing the most work.Given the wear and tear your coach had with the front end ,I would recommend replacing the calipars and the hoses together and both sides.I have serviced this type of problem many times with the gm p-30 or the c -30 trucks.This is more common on a motor home which is not used often .Sitting idle these coaches require more attention with most of the systems or mechanicals.

Scott

[outofcontrol]

Thank you for the ideas!

I spent the night reading on the internet, and I saw "collapsed rubber hoses" several times. Some suggest adjusting the rear brakes - hadn't thought of that- could have an effect. Another idea is to flush the fluid. It turns to water over time, and rusts internals/performs poorly. And sticky calipers.

I'm going to replace the rubber hoses, flush the fluid, and look into the calipers. I would guess there are re-build kits available instead of replacing the whole caliper? I've done this stuff 20 over on motorcycles, but this is my first RV...
Just went to the NAPA website- I can buy remanufactured calipers for $45-60 with new pads and hardware. That doesn't sound too bad. I was thinking $200. Looks like I'll have to turn the rotors if I'm putting new pads in. Re-pack/inspect the bearings while I'm at it... Just regular maintainence right?

-Kevin

[ALANSD]

You are right about brake fluid, it absorbs moisture and needs to be changed because of that.

[outofcontrol]

I bought the service manual and the owner's manual from AS, and niether say much about the brakes.

I need to know if I have GM JB7 or JB8 calipers, and if the hydroboost is 8,500 psi or 10,000 psi.

I think I need to find a service manual for the chassis if I keep running into these issues.

Thanks guys!

-Kevin

[overlander63]

Okay, pull to the left while braking could be:
Left lower ball joint
Left inner or outer tie rod end
collapsed right front brake hose
stuck right caliper
worn or sticking hardware (caliper slides)
misadjusted front wheel bearings
misadjusted rear brake shoes
lower control arm bushings

[noiva]

Originally Posted by overlander63

Okay, pull to the left while braking could be:
Left lower ball joint
Left inner or outer tie rod end
collapsed right front brake hose
stuck right caliper
worn or sticking hardware (caliper slides)
misadjusted front wheel bearings
misadjusted rear brake shoes
lower control arm bushings

I agree absolutely with Overlander. However, I did have a problem that caused the same issue. The outer rear axle seal was leaking into the brake housing. A new seal, and new set of pads cured the pulling, and gave me much better braking as well.

[scottanlily]

Replace the calipers and the hoses,flush the lines with fresh fluid ,getting the rotors turned gives you the chance to repack/replace wheel bearings.You mentioned braking effort was higher than normal to stop the coach,so check the rear brakes as well ,the rear hub seals leak oil onto everything eliminating stopping power there,very common on GM 30 series 1 ton chassis.Always make certain the rear differential fluid is full ,especially after rear brake service where there has been fliud leaking for awhile ,low fluid level in the Gm 14bolt corporate rear axle causes bearing failures at the outer wheel bearings and the rear differential bearings as well .You would be surprised how often the assumption that the level is ok without it actually being checked.

Good luck with your repairs.

Scott

[Chaplain Kent]

This does not help your problem but I just have to tell the story. On our way down to the Spring Fling Rally in Georgia I had a brake lock up outside of Chattanooga. I thought it would be OK but when we left the park in Georgia it began to squeal and I was sacred in the mountains. We stopped at the Wal Mart in Elijah, GA and they sent us to Payless Auto out in the country. Here I am a Northern guy who can barely speak the language with a motor home that is in desperate need of brakes. I squeal into his lot and the guy says it will be about an hour before he can look at it. We make lunch and prepare for the worse.
When it was our turn he confirmed we needed new front brakes. He goes to the phone dials and then walks to his back shelf and starts to pull off boxes of parts. He had everything in stock! If you think I was surprised he was shocked. One hour later Chummy had all new front brakes. Now it was time to pay the bill. I felt like Chevy Chase in Summer Vacation- open the wallet and give it all. He totals the bill and hands it over. $125.99. I think I will drive down to Elijah, GA for all of my service work from now on.

[noiva]

Originally Posted by Chaplain Kent

This does not help your problem but I just have to tell the story. On our way down to the Spring Fling Rally in Georgia I had a brake lock up outside of Chattanooga. I thought it would be OK but when we left the park in Georgia it began to squeal and I was sacred in the mountains. We stopped at the Wal Mart in Elijah, GA and they sent us to Payless Auto out in the country. Here I am a Northern guy who can barely speak the language with a motor home that is in desperate need of brakes. I squeal into his lot and the guy says it will be about an hour before he can look at it. We make lunch and prepare for the worse.
When it was our turn he confirmed we needed new front brakes. He goes to the phone dials and then walks to his back shelf and starts to pull off boxes of parts. He had everything in stock! If you think I was surprised he was shocked. One hour later Chummy had all new front brakes. Now it was time to pay the bill. I felt like Chevy Chase in Summer Vacation- open the wallet and give it all. He totals the bill and hands it over. $125.99. I think I will drive down to Elijah, GA for all of my service work from now on.

Chaplain Kent,

I told you to move down south, learn the accent, and you'll live so much better ! Look at all the "cheap" fixes I've found for the Silver Blimp (a.k.a.) 1989 370LE .

Best,

[nickcrowhurst]

On my truck, a violent pull to the left was caused by a rotor that needed replacing.There was no obvious visual sign. On the last three occasions I have carried out a major service on my various vehicles' brakes, I have fitted new rotors, rather than having them skimmed. Rotors are one item on vehicles that seem very low in price, so I would recommend new rotors, rather than skimming them. I just looked up a new rotor for a Ford Crown Vic, and it was $20, as an example.
Nick.

[swebster]

I do know not to tighten the belt using the pump body .

Hey, I resemble that remark.

Everything you're looking into replacing is a good idea anyway and as you are finding out - parts are pretty cheap for the P30. Sounds like a front end rebuild is a good idea.

On the type of brakes, I'm pretty sure it's the JB7 - but the chassis VIN (not the Airstream serial number) will tell you which system you have for sure. Call a GM truck dealer, tell then you need a price on calipers and a hydroboost and give them your VIN and ask them which system you have for your records.

On that Hydroboost leak you mentioned, which line is leaking? The pump itself provides hydraulic pressure to the hydroboost unit bolted to the frame. There is a high pressure line from the back of the pump into the unit. The master cylinder bolts to the back of the fixed unit and receives it's "boost" from the unit itself.

There is another high pressure line which goes from the unit to the power steering gear (boost for steering). There are then low pressure line (larger hoses with band clamps) which return the fluid back to the pump from the steering and brake systems.

If the low pressure sides are leaking (or weeping) it's not hyper critical and new hoses and clamps will quickly fix it, if it's high pressure then you'll notice hard pedal effort, steering effort, loss of large quantities of fluid etc.

No matter the cause of the leak I doubt it will cause more breaking on one side over the other.

Okay, pull to the left while braking could be:
Left lower ball joint
Left inner or outer tie rod end
collapsed right front brake hose
stuck right caliper
worn or sticking hardware (caliper slides)
misadjusted front wheel bearings
misadjusted rear brake shoes
lower control arm bushings

Lastly, Terry's advice has always helped me when troubleshooting issues on my motorhome. I think his list is right on target.

[outofcontrol]

First off... You guys are the greatest. Your ideas are right on point!

So I thought about it more, and I decided to start with the cheap stuff first, and keep going until I fixed the problem, or I found something obvious. I pulled off the left side brake hose and took it with me to NAPA. They only had the right side in stock, so I bought it, because I want to replace both anyway. I came home and decided to work on the right side while I waited for the L to come in tomorrow.

On the R side, I cracked open the line on one end of the hose, and no fluid leaked out. Hmmm
I removed the rest of the line and held it over my drip pan, still no fluid. Hmmmm.
I put some compressed air on the MC side, (125psi) and nothing.
With air on the caliper end, I got it to start weeping out with a couple glugs.
Seems to point toward a clogged/corroded/ruptured hose on the right side causing weak braking and a pull left.

Tonight I’ll install the right side hose, bleed the system, and go for a test. I don’t want to get my hopes up too much, but at least I think I found a problem.

The hose leaking off the hydroboost was a return line, and it was cracked all over, especially on the ends. It was like 40 cents + some clamps for that one.

Overlander,
Your list is spot on. I'm going to cruise down it until I find the problem. Are the "Lower Control Arm Bushings" the same as what I would call the "sway-bar bushings"? I'm not a truck/car guy. Motorcycles are my forte.

Thanks again!

-Kevin

[overlander63]

Originally Posted by outofcontrol

Overlander,
Your list is spot on. I'm going to cruise down it until I find the problem. Are the "Lower Control Arm Bushings" the same as what I would call the "sway-bar bushings"? I'm not a truck/car guy. Motorcycles are my forte.

Thanks again!

-Kevin

Kevin, the lower control arm bushings are the part that goes from the lower conrtol arm to the frame of the chassis. They are held in place by a pair of nuts on a threaded rod/shaft assembly. The lower control arm, for the not-so-truck-oriented guys, is the piece the bottom of the shock absorber hooks to. A quick (although no foolproof) way to tell if the bushings are bad, is to look straight on at the threaded rod/shaft, and see if the washers inside the nuts are in line with the bushings. If they are, chances are very good the bushings are okay, if the bushings seem to be sitting where you can see part of the bushing past the washer, the bushings are probably bad.

[outofcontrol]

Thanks all of you!!!

I got the new rubber lines on, bled out the lines, checked for leaks, made a few test stops in the driveway, then took her out on the street. Two more tests at slow speed, then I took her up to 25mph.

Amazing. Not only does she not pull, but she stopps much better! I guess it helps to have 2 brakes working in the front.

The PO helped me out by letting me know all the service the brake shop did. They must have flushed the brake lines when they did the brakes because the fluid was so clear I couldn't tell when the new stuff hit.

The only problem now is getting rid of my automatic compensation by slightly turning the wheel as I apply the brake. I even hit the brakes with my hands off the wheel, and it's perfect.

I'm temped to replace the rear flex hoses as a preventative move.

-Kevin

[scottanlily]

The front 1 ton brake rotors are not inexpensive .I do not recoomend the cheap bargain rotors made in china (not all china stuff is of poor quality) There is a difference ,these heavy coaches need the best quality parts .Napa certainly is an excellent place to go for parts.Going cheaper doesnt mean better ,you will get what you pay for i gaurantee it.

Scott

[scottanlily]

The lower GM p-30 control arm bushings are a shaft type .They do not use rubber bushings ,they have steel threaded ends that screw into the control arm and onto the shaft .they are very durable and made for these truck chassis also for any GM 1 ton of this type.They do where out do to the steel on steel thread style of operation and need to be greased regularly.A very common sound you hear when they are worn is a snapping or click that is distinctive when coming to a stop as the arm (shifts) slightly forward.Overlander 63 has described the light truck 1/2 ton or passenger car style setup used on most all gm cars and trucks ,caprice/impalas,camaros etc.The upper control arms on the 1 tons p-30 are the same as i described in the beginning of this post ,they too will snap or make a noise when the thread type bushing setup wears out .They are very stout however that is why they are used in the heaviest duty applications

Scott

[canny_banjo_man]

Not quite Heavy duty... My D/Ds car pulled 2 the left, so I done the strip down job, but first I remembered what I had bn taught, We drive on the LEFT over here, so our N/S brakes get all the Crap from the roads, also all the wet 2 wash it off agn, puddles & so on, the Right one don't get as washed as the left one does, NO puddles on the verge..lol, it WAS the off side calliper stickin, I stripped it down, new seals, new discs new pads, BOTH SIDES, the brake fluid was black, so I re-bled the entire system, after I replaced the rear shoes as well 4 Her... now Her brakes r BRILL, infact bttr than mine, I got time out in a couple of weeks, so I'll do Mine... I tried the " Free-Off method, where U get someone 2 pump the pistons out & lever them bk a few times, BUT it damages the seal in the master Cylinder if the reverse fast preasure turns the seal inside out... Yep that's a pain 2 sort...But I think renewal IS the SAFEST option, & 2 Me, whats a few £££'s compared with the cost of a childs life ???... Good luck...Chris.....