Brakes pulling to the right

[jbpoole Lurker Find all posts View Profile Close jbpoole]

My brakes pull to the right. I assumed this was due to a problem with the front left. I have new tyres and a wheel alignment was done. Front rotors and pads are good, no leaks and I've checked for stuck pistons and replaced the brake fluid. Interestingly, the manual I use specifically mentions the front left when it discusses bleeding. It talks of a method involving pressurising the master cylinder and giving 10 pumps at 1 per second with the bleed screw open. I've only tried the normal bleed method and am wondering if there could still be a big bubble halfway down the pipe. Any suggestions would be appreciated.

Jo

[glen_ep Addicted PP Member Find all posts View Profile Close glen_ep]

I doubt that would be caused by air, unless bleeding wasn't performed at all. I've bled my brakes many times (rears then fronts, never took note of which side), and rebuilt calipers a few times, but never had an issue with fluid. What is your normal bleed method?

I would assume it's either a poor contact issue (pad/rotor) or a caliper issue. It could be a problem on either side - one could be weak or one could be strong.

You said the front rotors and pads are good - what is their actual history?

Tyres can be ruled out by swapping the front tyres pass/driver.

Pads/rotors could be confirmed by swapping over pass/driver (separately from tyre swap, of course).

Test in a large parking lot, as road angles may affect the steering.

Can check which one is working harder by checking rotor temperature after testing (careful, hot!)

How did you check for stuck pistons? Best way is via a caliper rebuild - that way you know they'll be working very balanced. It would include cleaning/lubing the sliders.

[jbpoole Lurker Find all posts View Profile Close jbpoole]

Thanks for your reply glen_ep.

My normal bleed method is get someone to apply pressure to the brake pedal, open bleed and close it before they lift their foot. Repeat untill no bubbles (and in this case there was none from the start).

Rotors are original but measure within spec. I checked they weren't warped with a dial gauge as I have a seperate problem ( which I have been assuming was not related ) that on slow and mild braking to a stop there is some pulsing. It's like the braking force is increasing and decreasing over about a 1 second period. Doesn't seem to affect performance but is annoying mostly because I don't know what it is. Pads I put in a while back and look almost new.

To check for stuck rotors I just removed one pad put a thinner spacer in its place to stop pistons coming out too far and applied brake pressure. Pushed them back in and did it again a few times and then repeated for the other pad.

The rotor temperature test is a good idea. Might get a cheap infra-red thermometer. What did you mean "cleaning/lubing the sliders"?

The only other thing I thought may cause the one brake not to be so effective is if the ABS unit is allowing pressure to bleed from this brake. I'm not very familiar with them but reason that they must have to release pressure when they detect lack of rotation and since your foot is still hard down must bleed it off somewhere. Have you ever heard of these valves failing or passing?

Thanks again for your time

[glen_ep Addicted PP Member Find all posts View Profile Close glen_ep]

Wow original rotors! I'm surprised they could survive this long given they're meant to be machined at each pad replacement.

Does the pulsing frequency slow down with deceleration?
- If yes, the rotors are probably the cause of both issues. If you're skeptical try swapping them left/right and monitor changes.
- If no, I'd suspect ABS/sensors or master cylinder. I don't have ABS nor worked on it so can't offer any diagnostic tips there.

Another possibility could be front bearings - but I'd expect to hear grinding noises well before feeling brake issues. Something quick and easy to check though.

Cleaning/lubing sliders - the front pads slide along 2 steel rods. Dirt/grime can bog them up a bit preventing them from sliding in/out easily.

BTW there's also a load sensing proportioning valve in the rear connected to the panhard rod, which adjusts the breaking pressure between front and rear. That's just a FYI though, as I doubt it could ever cause left/right issues.

[jbpoole Lurker Find all posts View Profile Close jbpoole]

Sounds like it might be worth trying new rotors. They seem fairly reasonably priced. If you don't mind one more response do you think it's worth going slotted/holed/vented etc or sticking with plain ones? I never had any concerns with standard even towing a trailer down the Canning and across the Gunbarrel. Mind you my main concern is when my wife takes the kids to school. Should I avoid cheapies or are they all much of a muchness?
Thanks heaps for your time and advice.
Jo

[glen_ep Addicted PP Member Find all posts View Profile Close glen_ep]

No worries mate, happy to help where I can.

- Standard is fine in most cases.
- Slotted stays a little cooler but chews through the pads a little quicker. Advantage is longer continuous use (long down hills + towing) before brake fade.
- Slotted+holed for race cars. Not ideal for off road as they'll pick up too much junk and too weak.

Considering your main concern, standard rotors are fine but stick to quality brands. Keep the calipers/pistons/seals clean.

[Leethal Advanced Member Find all posts View Profile Close Leethal]

When you say it pulls to the right, is it severe and the steering wheel also turns as well or does the vehicle just "drift" to the right?
It may be the rear brakes at fault, if the rear brakes are unbalanced it cause pulling or "drifting" as well.
Usually a front brake issue will be more severe and tends to make the steering wheel turn as well where a rear brake problem is less pronounced.

A bit of information about your Prado will help as well, the late model ABS systems work very differently to the earlier systems as the brake pressure is generated in the ABS unit itself.

Lee

[jbpoole Lurker Find all posts View Profile Close jbpoole]

Thanks Lee. My Prado is a 3.4 L '98 model so I imagine has early ABS. The pulling while I wouldn't call it severe is sudden and just as the brakes are applied. With hands off the wheel at 20 km/h the steering wheel moves a few cm's to the right but then stabilises. At 95 km/h with a ton of camper trailer on the back it's similiar, pulls on first application but then goes straight so it's almost like the front right is coming on first but then the left is catching up.
Checked the rear discs and changed the pads the other day and it made no difference. One of the EFS shockies (RHS rear) is leaking which wouldn't help but the low speed test tends to indicate it's definitely a braking issue.

Jo

[Leethal Advanced Member Find all posts View Profile Close Leethal]

Hi Jo,
From your description I would say you have a caliper piston not fully "returning" when the brakes are released.
The O ring seal in the caliper is basically all the mechanical help the piston & pad combination have to move the pad away from the disc.
If the piston is tight it will not fully move away (we are talking a very small movement) and as such engage sooner than the other side. That you get a pull to the right then it stabilises indicates to me this is whats happening. If one caliper was fully seized then it would not stabilise but rather keep pulling more and more as you brake.
As Glen has already said, it is best to have both front calipers overhauled and perhaps machine or replace front rotors & pads depending on their condition.
I think that will fix your issue.
I am running DBA T3 slotted rotors (but then I got them at the T2 price because there was no T2's available at the time) and I find them a definite upgrade over the standard discs.

Lee

[Playdoh96 Member Find all posts View Profile Close Playdoh96]

Have you checked your front bushes in the front end including the steering rack. You might find they're soft or knackered and when you apply the brakes it's pulling the wheel back and mucking up the wheel alignment. Just a thought

[jbpoole Lurker Find all posts View Profile Close jbpoole]

Thanks guys,
looks like the best plan is new rotors and put a kit through the calipers. It wont hurt as it's probably maintenance that's due and will eliminate them as a cause, hopefully fixing it. Hi Playdoh96, bushes are all nolathane from when I had shocks and springs done a couple of years ago. They all seem ok so I'll start with the brakes and hopefully post the good news shortly....

[adrian5800 Advanced Member Find all posts View Profile Close adrian5800]

My brakes pull to the right. I assumed this was due to a problem with the front left. I have new tyres and a wheel alignment was done. Front rotors and pads are good, no leaks and I've checked for stuck pistons and replaced the brake fluid. Interestingly, the manual I use specifically mentions the front left when it discusses bleeding. It talks of a method involving pressurising the master cylinder and giving 10 pumps at 1 per second with the bleed screw open. I've only tried the normal bleed method and am wondering if there could still be a big bubble halfway down the pipe. Any suggestions would be appreciated.

Jo

My advice, when it comes to brakes if you're not 100% sure take it to someone who is.

A couple of years ago a guy came to me with a 105 series that had a clunk in the front end. He'd changed the pads a week or so before, when I removed the wheel there were no bolts holding the caliper on the bracket.. He still didn't understand the seriousness of the situation after I explained and showed him.

Ades

[Steve M Addicted PP Member Find all posts View Profile Close Steve M]

Pulsing through the pedal is definately due to warped discs (not uncommon in a Prado) does the steering shudder as well or just the pedal ?? If it's both the to start id replace front rotors. If it's just through the pedal then more then likely rears. Yes the rears do warp. I had a foot shudder in mine and was the rears..... Pulling to the right has been covered above and totally agree with Adrian. You sound like you have an idea. I have read on forums some people asking about what an overflow bottle does then they ask about pulling brakes apart. There the scary ones lol..... Cheers Steve

[jbpoole Lurker Find all posts View Profile Close jbpoole]

Have ordered PBR front rotors and caliper kits from Supercheap. About $115 for the lot. Might take a couple of weeks to get around to fitting them but then I'll post the results. Thanks for everyones interest and suggestions.

[fridayman Senior Member Find all posts View Profile Close fridayman]

Have ordered PBR front rotors and caliper kits from Supercheap. About $115 for the lot. Might take a couple of weeks to get around to fitting them but then I'll post the results. Thanks for everyones interest and suggestions.

I'm surprised that you can get rotors and caliper kits for $115 - I thought that the kits alone were about $60 a side...