Pulling left only on really hard braking (1 Viewer)

[NorCalFJ100]

I just finished an overhaul of my front braking system: Front Brake Caliper Replacement - Napa Eclipse NLA? Options? (All new OEM Calipers, Pads, Rotors and Brake Lines.)

I bled the brakes very well and was getting zero bubbles in the end. I went ahead and bed my brakes in as a final step. That went well. I was not getting any pulling.

Fast forward a few days later...now I am typically cruising the cruiser everywhere. Long gradual stops. Easy acceleration. Stops wonderfully for a 6,500lb 23 year old rig. However the other day I did come to an abrupt stop. The truck pulled very hard to the left. When stopping gradually I get no pull...even somewhat hard braking I don't. But if I really mash the brake pedal it pulls very hard to the left.

Things I have tried:

1. I have inspected fronts again. Nothing appears out of order.
2. I made sure the slide pins had plenty of grease.
3. I ran the truck on a dirt road and activated the ABS several times and came home to rebleed the system. RR, LR, LSPV, RF, LF. - The LR caliper didn't seem to want to push out too much fluid, but ultimately there were no bubbles. But it was noticeable the fluid did not gush out of that one.
4. Measured temperatures of the rotors twice...
   1. Driver side front: 205 - Passenger side front: 245 / Driver side rear: 197 - Passenger side rear: 212
   2. Driver side front: 202 - Passenger side front: 240 / Driver side rear: 300 - Passenger side rear: 270
5. Wheel bearings are all in check and also new. Trunnion bearings are new. Basically every moving part and bushing is all brand new OEM.

My truck stopped great prior to the front brake overhaul. I just had some really bizarre wear on some cheapo pads. I just wanted a nice baseline so I did the overhaul.

Thoughts?

 

[NorCalFJ100]

Any words of wisdom from the group before I drop loot on replacing the entire rear $y$tem?

I'm assuming I have a stuck caliper in the rear...BUT not sure why I have 35 degree temperature difference on the front rotors. But maybe this is normal or in tolerance?

 

[BILT4ME]

Any words of wisdom from the group before I drop loot on replacing the entire rear $y$tem?

I'm assuming I have a stuck caliper in the rear...BUT not sure why I have 35 degree temperature difference on the front rotors. But maybe this is normal or in tolerance?

I have experienced the same thing.

The issue could be that the LF is sticking slightly OR the RF is NOT moving as it should. Could also be the LR grabbing faster or the RR not grabbing as fast.

When bleeding, did you raise the LSPV arm to get full flow through the rear? I found I had some issue with less flow from one side before I raised the arm for bleeding.

Using the tempo gun to track it down is definitely worthwhile. Check all four.

I also would re-bed the brakes to see if it goes away. Mine would get better for a while, then slowly work back into an issue.

I also had all new SS cover lines (Slee) so mine was not hose issues. That's another possibility if you didn't change them.

 

[NorCalFJ100]

I have experienced the same thing.

The issue could be that the LF is sticking slightly OR the RF is NOT moving as it should. Could also be the LR grabbing faster or the RR not grabbing as fast.

When bleeding, did you raise the LSPV arm to get full flow through the rear? I found I had some issue with less flow from one side before I raised the arm for bleeding.

Using the tempo gun to track it down is definitely worthwhile. Check all four.

I also would re-bed the brakes to see if it goes away. Mine would get better for a while, then slowly work back into an issue.

I also had all new SS cover lines (Slee) so mine was not hose issues. That's another possibility if you didn't change them.

Good tip on the LSPV arm. I can try that next go around. I do have the Slee extended lines and new rubber up front.

What was strange is the LR really struggled to get fluid out of the caliper when I bled it. Maybe that's a sign the rubber hose is damaged. Now if the LR caliper was not functioning 100% wouldn't that lead to it pulling to the right?

I eventually wanted to overhaul the rear and baseline it. Perhaps I'll just knock that out now...

 

[Monty231]

I have a similar issue as you, however my rig pulls right. I have gone through the same trouble shooting as well.

I'm wondering now if I may be a bad brake line restricting flow under hard braking. Good luck finding the issue, I'll be following your thread.

 

[BILT4ME]

Good tip on the LSPV arm. I can try that next go around. I do have the Slee extended lines and new rubber up front.

What was strange is the LR really struggled to get fluid out of the caliper when I bled it. Maybe that's a sign the rubber hose is damaged. Now if the LR caliper was not functioning 100% wouldn't that lead to it pulling to the right?

I eventually wanted to overhaul the rear and baseline it. Perhaps I'll just knock that out now...

That's exactly where mine was having an issue. With new calipers from NAPA, new hoses, it ate the pads on the LR of mine. Then, after about 75K miles, I had to change that caliper and I can still feel it. I think that is an LSPV issue. I'm not ready to eliminate mine, but I do have it adjusted as high as I can get it, but I also have a 2.5" lift, so it's probably not high enough.

 

[NorCalFJ100]

I have a similar issue as you, however my rig pulls right. I have gone through the same trouble shooting as well.

I'm wondering now if I may be a bad brake line restricting flow under hard braking. Good luck finding the issue, I'll be following your thread.

Did you replace your brake lines? The only old ones I have are in the rear. I'm also running calipers that more than likely have 300k miles.

@BILT4ME have you replaced the LSPV? There was also a thread I found I think I saw you in there where someone had bought an inexpensive brake pressure test gauge. They were able to dial in the adjustment that way. I'll probably pick that up as well. SSBC A1704: Sure Stop Brake Pressure Gauge Kit | JEGS

 

[Monty231]

@NorCalFJ100 I did replace the frame to axle hoses when I did my lift a few years ago. They were not Toyota lines, I believe they were raybestos. So, I'm wondering if the budget brake lines are having issues. I've been debating getting the Slee stainless lines, but I may be looking into getting the correct length Toyota lines for my lift.

Also, I have had to replace the rear calipers twice previously, due to the fact the piston would not completely compress back into the housing and with pads installed would not go back over the rotors. This last time I replaced the rear pads all was good. Both previous times the calipers were replaced with O'Reilly remans, because they were in stock and I needed to get back on the road.

 

[BILT4ME]

Did you replace your brake lines? The only old ones I have are in the rear. I'm also running calipers that more than likely have 300k miles.

@BILT4ME have you replaced the LSPV? There was also a thread I found I think I saw you in there where someone had bought an inexpensive brake pressure test gauge. They were able to dial in the adjustment that way. I'll probably pick that up as well. SSBC A1704: Sure Stop Brake Pressure Gauge Kit | JEGS

I have not replaced my LSPV.

I have considered the brake pressure test gauge, but it appears it would be a HUGE amount of work to install, test remove at each location., then bleed each time. I realize it's done at the bleeder, but that's assuming you have the room to install.

 

[flintknapper]

Good tip on the LSPV arm. I can try that next go around. I do have the Slee extended lines and new rubber up front.

What was strange is the LR really struggled to get fluid out of the caliper when I bled it. Maybe that's a sign the rubber hose is damaged. Now if the LR caliper was not functioning 100% wouldn't that lead to it pulling to the right?

I eventually wanted to overhaul the rear and baseline it. Perhaps I'll just knock that out now...

Rear calipers are easy to rebuild...if you don't want to purchase new/remans.

 

[NorCalFJ100]

I have not replaced my LSPV.

I have considered the brake pressure test gauge, but it appears it would be a HUGE amount of work to install, test remove at each location., then bleed each time. I realize it's done at the bleeder, but that's assuming you have the room to install.

I did look very tedious to use that gauge. But it seems like it had good results.

@flintknapper IF I was to buy new OEM I would keep the old ones to rebuild. There is something about shiny new OEM parts that really makes me happy. LOL.

 

[NorCalFJ100]

I guess the consensus is that the rear calipers quite possibly need some attention.

Can you mudders think of anything that could be off up front? I just want to eliminate that option. I will focus on the rears.

Any other troubleshooting tips that I haven't listed in my original post?

 

[Grandlooser]

When you say "pulls" does the steering wheel force into that direction? If so I'd be wasting no time inspecting the rear.

 

[operatorTRP]

Make sure your tire tread is at similar tread levels. I was running MT's and put a spare on that was at a higher tread depth and it really pulled during braking. easy to swap front tires and see if the pull changes direction? Just a thought.

 

[NorCalFJ100]

When you say "pulls" does the steering wheel force into that direction? If so I'd be wasting no time inspecting the rear.

Yes, it pulls very hard to the left, but only when I really mash the brake pedal. If I gradually stop it is perfectly straight.

Make sure your tire tread is at similar tread levels. I was running MT's and put a spare on that was at a higher tread depth and it really pulled during braking. easy to swap front tires and see if the pull changes direction? Just a thought.

Good tip! Fortunately all 4 tires have equal wear.

 

[NorCalFJ100]

Okay so for the sake of baselining, I just ordered new OEM rear calipers, pads, rotors, brake lines and fitting kit. The only thing left is about $600 worth of e-brake parts. Haha...but that seems to work "okay" so I am leaving that for now.

 

[OffRoadScott]

I guess the consensus is that the rear calipers quite possibly need some attention.

Can you mudders think of anything that could be off up front? I just want to eliminate that option. I will focus on the rears.

Any other troubleshooting tips that I haven't listed in my original post?

I would also check the ABS sensors if you rig is equipped with ABS. I was having a similar issue, it would pull right when I would brake no matter the pedal pressure.

 

[Rusty Marlin]

When you say "pulls" does the steering wheel force into that direction? If so I'd be wasting no time inspecting the rear.

Not necessarily.
I was having the exact same problem except pulled to the right, hard enough you had to counter steer or you'd go in the ditch.
Like the OP I changed everything, soft lines, carrier pins, pads, hats, everything but the calipers. Final fix was change the calipers. Truck brakes dead strait and true now.

 

[clx16]

I had mine pulling to the left and forcing me to counter. I put some brake grease under the rubber boots for the pistons on the rear left caliper and worked them in and out until they were smooth. stops straight now. cheap and fairly fast.

 

[Rusty Marlin]

I had mine pulling to the left and forcing me to counter. I put some brake grease under the rubber boots for the pistons on the rear left caliper and worked them in and out until they were smooth. stops straight now. cheap and fairly fast.

That's usually all it takes, exercise all the parts and grease what needs to slide. But sometimes, that doesn't work. Glad you got off with the cheap fix.
I had bled my brakes about a month before I changed the calipers (when I changed the LSVP and master cylinder), when I went to exercise the pistons, the seals died and rusty brake fluid poured out. New calipers went in at that point as they were not rebuildable with the corrosion in the piston bores.