Pull to right when braking (1 Viewer)

[etarasoff]

Hi guys,

It's been awhile since I've been around since a new Sprinter van has been the obsession of my automotive ADD over the last year.

But I'm back...and with a problem!

Background:

When I last left off with my LX, I had performed a brake job (in several stages over a couple of months). The car mostly sat in the driveway during this period, and after. I did the front brakes first as part of a knuckle job. Car stopped beautifully. I later went to do the rear bearings, calipers, rotors, etc. At that time, I also replaced all the soft brake lines on the vehicle.

After that, the car would pull to the right when braking, sometimes very heavily, but always to the right. Having just done the rear brakes, and having used some "Centric" brand calipers, I figured that maybe there was an issue with the calipers.

Then the truck sat for about 6 months...

Where Things Sit Now:

This weekend, I replaced both rear calipers with new one but the problem persists. I then noticed after a test drive that the FRONT RIGHT wheel is significantly hotter than the left front wheel. So I figured that maybe the left front caliper has a sticky piston or something, causing a reduced braking pressure. But upon inspection, all 4 pistons seems to operate smoothly. I did test to see if all 4 pistons move when the brake pedal is applied. They did, but not evenly, and my wife had to pump the brake pedal a couple of times to get the pistons to pop back out. For what it's worth, the front right caliper acts the same. I don't have the automotive experience to know if that is normal or if they should all pop out almost instantly and evenly.

Ideas?

Knowing what I've done, and the symptoms I've described, I'd love to get some ideas on things to check out. Kind of at a loss for what to do now.

Thanks!

 

[BILT4ME]

There are a few possibilities.
1) The right front caliper has sticky pistons and they are not retracting as fast or as much as they need to.
2) The left front caliper has sticky pistons and they are not pushing out as fast or as much as they need to.
3) You have air in the line that the lines need to be bled again, in order, RR, LR, LSPV, RF, LF.
4) Take it for a drive on loose gravel and brake hard enough to activate your ABS multiple times.
5) Re-bleed all your brakes in the order done previously
6) Repeat steps 4 and 5.

Also, check your tire pressures in the somewhere. Also double check your front wheel bearing adjustment, as a loose wheel bearing will mess with how the front brakes work since the caliper is mounted independently from the hub and rotor.

Most likely it is the RF caliper or air in the system. The pressure is easy to overcome. It is when the pressure is released that the lines must allow the pressure to RELEASE from the caliper fully and that is USUALLY where the problem lies.

Did you install new hoses as well? If these happen to be the original hoses, they could fail internally and act like a check valve and allow pressure to go out, but only release slowly.

 

[etarasoff]

There are a few possibilities.
1) The right front caliper has sticky pistons and they are not retracting as fast or as much as they need to.
2) The left front caliper has sticky pistons and they are not pushing out as fast or as much as they need to.
3) You have air in the line that the lines need to be bled again, in order, RR, LR, LSPV, RF, LF.
4) Take it for a drive on loose gravel and brake hard enough to activate your ABS multiple times.
5) Re-bleed all your brakes in the order done previously
6) Repeat steps 4 and 5.

Also, check your tire pressures in the somewhere. Also double check your front wheel bearing adjustment, as a loose wheel bearing will mess with how the front brakes work since the caliper is mounted independently from the hub and rotor.

Most likely it is the RF caliper or air in the system. The pressure is easy to overcome. It is when the pressure is released that the lines must allow the pressure to RELEASE from the caliper fully and that is USUALLY where the problem lies.

Did you install new hoses as well? If these happen to be the original hoses, they could fail internally and act like a check valve and allow pressure to go out, but only release slowly.

Did replace all the soft brake hoses.

Thanks for the reply. Although I didn't mention it, I did do a series of hard brakings and have bled the system 3 times now...although I did it in this order each time as per some other threads I read about bleeding: RR, LR, RF, LF, LSPV.

Is there any way to diagnose #1 or #2 in a conclusive way?

 

[BILT4ME]

Did replace all the soft brake hoses.

Thanks for the reply. Although I didn't mention it, I did do a series of hard brakings and have bled the system 3 times now...although I did it in this order each time as per some other threads I read about bleeding: RR, LR, RF, LF, LSPV.

Is there any way to diagnose #1 or #2 in a conclusive way?

Unfortunately no, unless you have the pressure gauge setups to hook inline and do it 100% the correct way. I do not have that setup.

I am fighting a RR caliper that is hanging up, and I cannot determine why. I have replaced the caliper and the soft lines, and bled them a few times. Since mine is on the rear, I am inclined to think mine is an LSPV issue, and not just a caliper.

 

[etarasoff]

Unfortunately no, unless you have the pressure gauge setups to hook inline and do it 100% the correct way. I do not have that setup.

I am fighting a RR caliper that is hanging up, and I cannot determine why. I have replaced the caliper and the soft lines, and bled them a few times. Since mine is on the rear, I am inclined to think mine is an LSPV issue, and not just a caliper.

My understanding was that the LSPV just regulated pressure front vs rear, but did not come into play left vs right. I could/likely be wrong about that, though.

 

[BILT4ME]

My understanding was that the LSPV just regulated pressure front vs rear, but did not come into play left vs right. I could/likely be wrong about that, though.

Correct, it does not do any left-right regulation, only rear pressure total.

It's frustrating to figure out what it is unless I'm not getting the LSPV bled properly and the bubbles are keeping the LEFT one from NOT operating.... I'm not sure. I know my thermal gun shows the right side about 40°F higher than the left, and a new set of cheaper pads only lasted 3000 miles on the RR. I just need to spend some quality time with it.

 

[turboed83]

If it were a sticking caliper it would be the left front. If the LF caliper is sticking when you apply the brakes there would be a pull to the right. Could also be a loose wheel bearing on the right side. I would place my money on calipers though. I bought napa reman calipers and havent had any issue. Maybe try to bleed more. There may also be air in the line to the left caliper. Something is going on with the left front caliper.

 

[etarasoff]

Well, I have an update on my progress today. Although I'm not sure where to go next based on what I observed, maybe someone here can have mercy on me and make sense of it.

1) Bled the system twice. Really went to town on the LF too. No change in driving behavior after this.
2) Swapped the two front tires left to right. After that, the vehicle PULLED TO THE RIGHT (or strongly drifted) while driving, not on the brakes, but didn't really seem to pull to the right any more when on the brakes. In other words, braking produced no noticeable change in feeling.
3) Swapped the two front tires back around again. After that, the vehicle TRACKED STRAIGHT while driving, but there was a very noticeable pulling to the right when braking. Vehicle immediately starts tracking straight as soon as the brake pedal is released.
4) Bought an IR heat gun at Autozone and took a 15 minute drive down the freeway, coasting to a stop without using the brakes. PS hub and caliper were about 5-8 degrees F higher than DS. Exhaust Y-pipe was measuring about 250 degrees F.
5) Drove around town for about 15 minutes more, using the brakes heavily. PS hub and caliper were about 10-15 degrees F higher than DS. Exhaust Y-pipe was measuring about 500 degrees F. Frame near the Y-pipe was about 50 degrees F warmer than the DS.

 

[Funner]

Maybe recheck wheel bearing tightness.

 

[slow95z]

so what method does everyone like best for wheel bearings? i used the fish scale but i have heard others tighten them so a certain ft lbs then spin and back off??

 

[Heckraiser]

I had a similar problem a while back. When the truck was new to me, I replaced one front caliper knowing it was bad. Turns out replacing both calipers was the way to go. Issue resolved, brakes straight and strong now. Both front calipers appeared to be working fine prior to replacing the 2nd one (pistons were moving about the same), but any small difference in braking force will translate to driving issues. I used Advance Auto remanufactured calipers. An OEM rebuild kit will work just as well for less $, but more time.

 

[turboed83]

I second checking wheel bearing/trunion bearing. Basically check everything on that right knuckle. Maybe caused uneven wear on that RF tire. Also, are you activating the abs pump when bleeding the system ? I myself like many others ended up deleting my abs which greatly improved my braking. They easily trap air and I suspect many of them are wearing out due to age. The extra heat indicates increased resistance in that wheel.

 

[etarasoff]

I second checking wheel bearing/trunion bearing. Basically check everything on that right knuckle. Maybe caused uneven wear on that RF tire. Also, are you activating the abs pump when bleeding the system ? I myself like many others ended up deleting my abs which greatly improved my braking. They easily trap air and I suspect many of them are wearing out due to age. The extra heat indicates increased resistance in that wheel.

Check the trunnion bearings? That's not even cool to say that after the epic knuckle job I did with 5000 rolls of paper towels, fish scales and lots of cursing. LOL

Some additional info I should have shared originally but didn't. Before I did anything, the truck had a pull to the right. After the front brake job (+ full knuckle job), it still had the same pull. I set the toe in at that point and it resolved it.

Wondering if there is something weird with my tires potentially? They're 255 Cooper ST's (not STT's) and are not exactly the smoothest things around. What's weird as I observed above is that I track straight and have a brake pull, but if I swap fronts left and right, I get a pull all the time but no extra brake pull. Seems like if it were bearings I'd have a pull all the time.

At any rate, as has been suggested, my next plan of action will be to try activating the ABS and rebleeding. If nothing comes from that, I'll check bearing preload. If nothing there, new calipers on both sides. And if that doesn't work, I'll try doing something with the tires. Any other suggestions?

 

[Funner]

Out of an abundance of caution I would still double check the wheel bearings, IIRC 30ftlbs is the sweet spot. This should take about 15 minutes to do.
Please clarify for us-
The first post you indicated that after front brake job, the truck stopped beautifully.
Later you seem to say the truck pulled to the right before and after the brake job? Which statement is most accurate?
Assuming all else is tight and double check the wheel bearings and caliper bolts, then I would look at TRE's or be thinking something jangly is going on with the tires. Rotate front to back to get the two possibly jacked up tires in the back and hopefully the rears are okay, drive and report back.
Otherwise, there are things like oil on front left pads from the front axle service that has ruined those pads? The pads can be pulled and replaced without removing the calipers.

 

[FJP971]

If the problem was there before you did the brakes I would say check your alignment. Caster and camber differences can cause a pull while braking. Like Funner said, we need clarification on when the problem started.

 

[turboed83]

rotate rear wheels to the front. That would eliminate a tire pull issue. You can easily check alignment with a tape measure. FYI wheel bearings seem to come a little loose often. Also knuckle studs loosen and even shear off. Just triple check all of that. Are your front brake pads wearing unevenly ? If you have a sticking caliper you should get pad wear on the piston side. Also check your caliper slide pins. They can corrode or gunk up and not let the caliper slider correctly to return to open position. Wire wheel them and grease them up good. I would still consider removing the abs pump regardless. I was a little weary and took forever to pull the trigger. Easily one of the best things I did. Stops WAY better now. Also eliminated the LSPV. Best part is it is free and you can do in about an hour.

 

[CruiserDave]

When mine did that it was the front right wheel bearing worn/loose.
Replaced and tightened all is well now.

 

[Tedward]

Alignment and castor, as mentioned, could be the problem.

I had a slight pull under braking that finally changed some for the better. This was after new front control arm bushings in one side. Just did the other side but have not driven it yet. Will find out in a few days if it's gone.

In the past the calipers, rotors, pads, and brake hoses were changed with no effect on the slight pull under braking.

Good luck!

 

[LS1FJ40]

Simple solution: Buy a 91 or 92. In order to stop you just let off the gas.

 

[etarasoff]

Out of an abundance of caution I would still double check the wheel bearings, IIRC 30ftlbs is the sweet spot. This should take about 15 minutes to do.

That's #2 on my list after the ABS-activation-then-rebleed.

Please clarify for us-
The first post you indicated that after front brake job, the truck stopped beautifully.
Later you seem to say the truck pulled to the right before and after the brake job? Which statement is most accurate?

Yeah, I didn't describe that very well. Here's the full history (it's long, sorry)...

1) Before knuckle/brake job, truck pulled to the right while driving (not just braking). Took vehicle for an alignment and they told me caster was within range. They adjusted toe-in with no effect and suggested there might be a minor brake pull causing the problem.
2) I did a full knuckle/brake job (which also included new OEM spindles) and the ride improved dramatically while some minor vibration disappeared. But truck still pulled to the right exactly the same as before.
3) Right after #2 (like the same day), I adjusted the toe-in to point the tires in a little more after reading that bigger tires benefit from more toe-in. Went for a test drive and the truck drove straight without a pull. To the best of my knowledge, there was no brake pull but there's a chance it was there and I just didn't notice as I wasn't daily driving the vehicle.
4) Parked truck and over a few weeks here and there did the rear bearings/seals/brakes. Replaced all soft lines at the same time.
5) Went for a test drive after #4 and noticed the pull to the right when braking.
6) Parked truck for several months and played with my new Sprinter van. Only use the truck saw was starting the engine once a week and moving it back and forth on the driveway.
7) Returned to truck this weekend. Replaced rear calipers and truck still pulled to the right when braking. Tracked straight when not on the brakes.
8) Swapped LF tire for RF tire and took another test drive. After this, the truck pulled to the right while driving and not on the brakes. Stepping on the brakes *did not* produce a sensation of pulling to the right in the steering wheel like before the tire swap.

Assuming all else is tight and double check the wheel bearings and caliper bolts, then I would look at TRE's or be thinking something jangly is going on with the tires. Rotate front to back to get the two possibly jacked up tires in the back and hopefully the rears are okay, drive and report back.
Otherwise, there are things like oil on front left pads from the front axle service that has ruined those pads? The pads can be pulled and replaced without removing the calipers.

Will check the bearings and add TREs to the list.

Pads, rotors, etc are definitely clear of grease or oil (checked that over the weekend while checking the pistons). Also cleaned the snot out of it all again with Brake Cleaner just to be sure with no effect.

If the problem was there before you did the brakes I would say check your alignment. Caster and camber differences can cause a pull while braking. Like Funner said, we need clarification on when the problem started.

Please see my reply to Funner. Caster and other things were in spec the last time the truck was on a rack. Only 1" bushings and am not putting on my TJM lift until I get this issue sorted out first.

rotate rear wheels to the front. That would eliminate a tire pull issue. You can easily check alignment with a tape measure. FYI wheel bearings seem to come a little loose often. Also knuckle studs loosen and even shear off. Just triple check all of that. Are your front brake pads wearing unevenly ? If you have a sticking caliper you should get pad wear on the piston side. Also check your caliper slide pins. They can corrode or gunk up and not let the caliper slider correctly to return to open position. Wire wheel them and grease them up good. I would still consider removing the abs pump regardless. I was a little weary and took forever to pull the trigger. Easily one of the best things I did. Stops WAY better now. Also eliminated the LSPV. Best part is it is free and you can do in about an hour.

On the calipers, you're talking about the rears I guess because the fronts have 4 pistons, 2 on each side. But yeah, replaced the rear calipers with no effect. Planning to check some of that other stuff.

When mine did that it was the front right wheel bearing worn/loose.
Replaced and tightened all is well now.

Definitely planning to check the bearings (#2 on my TODO list at the moment) but I have a feeling it's not that.

Alignment and castor, as mentioned, could be the problem.

I had a slight pull under braking that finally changed some for the better. This was after new front control arm bushings in one side. Just did the other side but have not driven it yet. Will find out in a few days if it's gone.

In the past the calipers, rotors, pads, and brake hoses were changed with no effect on the slight pull under braking.

Good luck!

Thanks. Do you know of any way to check control arm bushings besides doing a visual inspection? Control arm bushings are on my project list and I even have new ones as part of some kit I picked up from Akella last year but hoping to save that for another day...

Simple solution: Buy a 91 or 92. In order to stop you just let off the gas.