Vehicle Moves Right When Low Braking

[BarnacleBOY]

Hey hey friends.

I have a 2000 Toyota Prado 90 series with the 3.0kzte engine.

The vehicle was pulling right when braking, so I replaced the front and rear discs and pads, thinking the discs were warped (one was actually). It didn't fix the issue. I think took the front calipers off (thinking the left one had a problem) and replaced all the seals in them with new dust covers. Ran new brake fluid through the system and went for a test drive.

Under heavy braking (emergency stopping), the vehicle stops fine and in a straight line. However, when lightly using the brakes to slow down, it pulls to the right. I've in the Australian forums that it could be the ABS module. Has anyone had a similar issue and successfully fixed it?

 

[Shayne]

Have you looked at the rear brakes ?

 

[BarnacleBOY]

Have you looked at the rear brakes ?

Thanks for the reply.

I did. New discs and pads on the brakes too. I also replaced the pins and the rubber seals. I didn't service the piston or dust covers though.

 

[fbnss]

assuming there is one would pulling the abs fuse be a simple test?

 

[BarnacleBOY]

assuming there is one would pulling the abs fuse be a simple test?

There is a 60amp fuse, and it hasn't blown. I can't read my fuse box 100% some of the writing has faded, but I can try seat the fuse better?

 

[fbnss]

If it's like an 80, pull the fuse and the abs will not be working, then you'll be able to tell whether it's that making it pull right?

 

[MisterCruiser]

Is one wheel (front or back) hotter than the others after doing the light braking, maybe indicating a sticking caliper. I've read a flexi hose deteriorating on the inside can cause issue with the fluid affecting the piston applying / releasing etc, but I believe it's very rare for modern flexi hoses to do this.

Is there any play in the wheel?
Worn bushings, etc?
Tyres?

Strange it only does it on light braking though.

 

[BarnacleBOY]

Is one wheel (front or back) hotter than the others after doing the light braking, maybe indicating a sticking caliper. I've read a flexi hose deteriorating on the inside can cause issue with the fluid affecting the piston applying / releasing etc, but I believe it's very rare for modern flexi hoses to do this.

Is there any play in the wheel?
Worn bushings, etc?
Tyres?

Strange it only does it on light braking though.

So I haven't looked at the wheel bearings properly, doesn't seem to be any play though.
I have rotated and realigned the tyres, so it isn't them.

I'll look at the wheels, and feel if the right one is getting hotter than the left.

The hoses aren't bulging, and the brakes aren't dragging the wheel, because it doesn't pull when driving normally, the alignment is perfect.

 

[Shayne]

ABS should not be involved in light braking but pull the fuse like Nick suggests and test the brakes when you have no abs at all .

Seems very improbable because I would assume brakes have been bled several times along with all you have done so far but an air pocket trapped in one line will stay in one line and provides a cushion so fluid is not as effective .

Has me thinking about bushes , particularly rear trailing arm and pan hard rod . There is no alignment to set at the rear and when bushes become worn the axle can pivot just slightly but enough to steer a little .
I only worked out that was happening with my swb 90 because it felt unbalance at high speed on long sweeping motorway bends but i suppose it might have been noticeable under gentle braking which wouldn't really have registered in my mind as a full brake overhaul was pending anyway .

 

[BarnacleBOY]

ABS should not be involved in light braking but pull the fuse like Nick suggests and test the brakes when you have no abs at all .

Seems very improbable because I would assume brakes have been bled several times along with all you have done so far but an air pocket trapped in one line will stay in one line and provides a cushion so fluid is not as effective .

Has me thinking about bushes , particularly rear trailing arm and pan hard rod . There is no alignment to set at the rear and when bushes become worn the axle can pivot just slightly but enough to steer a little .
I only worked out that was happening with my swb 90 because it felt unbalance at high speed on long sweeping motorway bends but i suppose it might have been noticeable under gentle braking which wouldn't really have registered in my mind as a full brake overhaul was pending anyway .

Thank you for the advice. I looked at the pan hard rod and the rear trailing arms when the vehicle was having it's front propshaft fitted (long story, it exploded on the highway while I was driving at about 120km/h, fortunately no damage to the car, only to the propshaft which has now been fixed).

So the bushes are old, but everything feels really sturdy. I will take it for another test at the suspension company to get an idea if that could be the issue. Maybe that is what is happening. The vehicle feels weird in corners, but I put that down to being top heavy, and the fact that I'm used to smaller cars.

 

[Shayne]

They might look good and feel solid when you try to move them by hand but its a high car over a ton in weight and 20 odd years old . Time takes its toll on all things so its probable your not looking for a single problem but rather the combined effect of lots of little things which in themselves are of no importance .

We call it character Take a look here at some common issues most of us have tackled sort of in our own time as and when time and inclination suits . Cruisers rarely need repair but age makes them a sort of rolling restoration project , because with a little TLC they will out last us .

https://www.landcruiserclub.net/community/threads/90-series-mods-and-repairs-faq.123578/

 

[MisterCruiser]

It can be hard to detect the worn bushings too sometimes. For example, I had a worn arm bushing on the rear upper trailing arm, the arm that mounts on the axle to the body or chassis of my 120. When the cruiser was on a lift the play wasn't obvious, but when looking at it over a pit with the weight of the cruiser on the ground as normal I could move this arm by hand. With the lift carrying the weight of the cruiser and the suspension hanging down it didn't show up by hand.

Just something worth noting, give everything a good poke with a pry bar

 

[MikeJak]

Do uou have a suspension lift on your 90? If so a slight pull when light braking would be quite normal unless you install a pan hard correction kit. Lifting the suspension but not changing the pan hard set up moves the rear axle to the left (about 1” to the left with a 2” lift)

 

[BarnacleBOY]

Thank you so much for the replies everyone.

So I don't have a lift kit, but bigger tires are fitted, which I want to change to the original size.

As for some interesting news, the front control arms are unfortunately finished - at least the bushings are. I'm not sure if the ATF fluid from the power steering made the rubbers wear out (my power steering pump has been giving me hassles, need to take it out and fit the gasket kit), but seems to have done something on the left hand control arm.

I need to replace the lower control arms and ball joints. I'm not sure if this is going to fix the issue, but maybe it will help. Definitely help with stability.

 

[MikeJak]

Thank you so much for the replies everyone.

So I don't have a lift kit, but bigger tires are fitted, which I want to change to the original size.

As for some interesting news, the front control arms are unfortunately finished - at least the bushings are. I'm not sure if the ATF fluid from the power steering made the rubbers wear out (my power steering pump has been giving me hassles, need to take it out and fit the gasket kit), but seems to have done something on the left hand control arm.

I need to replace the lower control arms and ball joints. I'm not sure if this is going to fix the issue, but maybe it will help. Definitely help with stability.

Loose bushes on the lower arms would definitely mess with braking as they would change geometry. It’s not too bad of a job. Can be rebushed or roughtrax has them with the bushes. For the ball joints I’d suggest 555 or oem, I’ve had lower ball joints from milners and from roughtrax and they don’t last very long..

 

[BarnacleBOY]

Great update coming today!
It turned out the bushes on the lower control arms were the culprit. They have now been replaced, and the vehicle feels SO MUCH better on the road. It doesn't pull right when braking anymore, and it feels solid.
That is one big issue off the table. Unfortunately, it meant the entire front suspension was replaced. It's great, because it will last a long time, unfortunate in that it cost an absolute bucket load.

I'm hoping that this weekend we can tackle the power steering pump leak, and after that it can go for roadworthy.

There is, unfortunately, a rear main oil leak, it's so little, so I might be able to clean it and get it through roadworthy, and when I have the time, handle the repair. It's a massive job and I don't have all the tools and space to do it properly. Will need to see though.

The missus drove the Prado home and is happy, so that is the most important thing right now. Next is roadworthy!

 

[Shayne]

They all start leaking there after 20 years , once I found a rebuild kit and it cost almost as much as a complete new aftermarket rack .