Please help, WTF is wrong with my RR brake?

[69/19Ranger]

I bought this truck new march 2020. Never had any problems or repairs until now.

This is the second time I have replaced rear pads and rotors. Replaced all pads and rotors April 2022 . Had no problems the first time.

Recently rotated my tires and discovered that my rear brakes were super thin. Way premature considering the fronts have 4-5mm remainungon the front with even wear left to right.

Installed new pads and rotors march 14 and it seemed like it all went off without a hitch. This past weekend me and my wife were cruising around with the windows down and she notices a couple times smelling burning brakes. Get home and check it out. RR only is burning up. Left side is fine.

I let it cool most of the rest of the day. Jack it up, put it in neutral, rotate the wheels by hand, RR dragging like hell. Left side totally normal. Pull the wheel off, have my wife pump the brakes and release. I crack open the bleeder screw and nothing. I take the caliper off which it is rather difficult to get off. Test rotational force with caliper removed and it seems completely normal.

I force the caliper piston back in a bit, reinstall caliper, test rotational force again. Seems normal. Pump the brakes, go back around to retest, dragging again. I go another round. After driving the caliper piston in again I reset the piston using only the parking brake lever this time. Same result: apply, release tetest and dragging. Lookslike I have a sticky caliper.

I go looking for answers. I come across all kinds of stories about failed rear calipers mostly on one side.
So I get a new caliper from the dealer yesterday. Install it, bleed it out.

This morning I get to work and check it out and RR hotter way than LR or either front.

I go looking for answers again. Find a thread on ranger5g about uneven tension on rear parking brake cables with p-brake disengaged. According to the descriptions in this thread everything looks and feels OK.
So I loosen up the adjustment nut at the handbrake lever and go for a test drive. Come back and measure rotor temperatures. Both fronts at about 145° LR @ approx 155° RR at about 265°
Before I leave to go home I loosen up the adjustment a bit more. Get home (6 miles) all brakes about 160° except RR at 285° on the friction surface and 315° at the hat.


I have never felt any dragging while driving before or after most recent brake job. Tonight, I coasted in neutral for about 1/8 of a mile before having to apply the brakes for traffic. Could not discern the brakes dragging.

My coworker is convinced it's a warped rotor despite being brand new. Wants me to measure runout.

Came across a similar situation on a quora thread hypothesizing a sticky ABS valve on the affected channel.
This is a possibility, but the very first test (pump, release, crack bleeder)would seemingly have ruled this out.

There is one weird thing I did in the process.
I flushed the brake fluid
To start, I pumped most of the fluid out of the reservoir using the braked pedal through the RR Caliper bleeder screw.
Normally I vacuum the old fluid out first but I left my fluid evacuator at the shop.

Looked at identifix for some insight and found nothing applicable.

Currently I'm at a loss.

I'm going to take the RR parking brake cable loose of the lever this weekend and retest.

If anyone has any ideas here I would appreciate the help.

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[RangerBill]

I bought this truck new march 2020. Never had any problems or repairs until now.

This is the second time I have replaced rear pads and rotors. Replaced all pads and rotors April 2022 . Had no problems the first time.

Recently rotated my tires and discovered that my rear brakes were super thin. Way premature considering the fronts have 4-5mm remainungon the front with even wear left to right.

Installed new pads and rotors march 14 and it seemed like it all went off without a hitch. This past weekend me and my wife were cruising around with the windows down and she notices a couple times smelling burning brakes. Get home and check it out. RR only is burning up. Left side is fine.

I let it cool most of the rest of the day. Jack it up, put it in neutral, rotate the wheels by hand, RR dragging like hell. Left side totally normal. Pull the wheel off, have my wife pump the brakes and release. I crack open the bleeder screw and nothing. I take the caliper off which it is rather difficult to get off. Test rotational force with caliper removed and it seems completely normal.

I force the caliper piston back in a bit, reinstall caliper, test rotational force again. Seems normal. Pump the brakes, go back around to retest, dragging again. I go another round. After driving the caliper piston in again I reset the piston using only the parking brake lever this time. Same result: apply, release tetest and dragging. Lookslike I have a sticky caliper.

I go looking for answers. I come across all kinds of stories about failed rear calipers mostly on one side.
So I get a new caliper from the dealer yesterday. Install it, bleed it out.

This morning I get to work and check it out and RR hotter way than LR or either front.

I go looking for answers again. Find a thread on ranger5g about uneven tension on rear parking brake cables with p-brake disengaged. According to the descriptions in this thread everything looks and feels OK.
So I loosen up the adjustment nut at the handbrake lever and go for a test drive. Come back and measure rotor temperatures. Both fronts at about 145° LR @ approx 155° RR at about 265°
Before I leave to go home I loosen up the adjustment a bit more. Get home (6 miles) all brakes about 160° except RR at 285° on the friction surface and 315° at the hat.


I have never felt any dragging while driving before or after most recent brake job. Tonight, I coasted in neutral for about 1/8 of a mile before having to apply the brakes for traffic. Could not discern the brakes dragging.

My coworker is convinced it's a warped rotor despite being brand new. Wants me to measure runout.

Came across a similar situation on a quora thread hypothesizing a sticky ABS valve on the affected channel.
This is a possibility, but the very first test (pump, release, crack bleeder)would seemingly have ruled this out.

There is one weird thing I did in the process.
I flushed the brake fluid
To start, I pumped most of the fluid out of the reservoir using the braked pedal through the RR Caliper bleeder screw.
Normally I vacuum the old fluid out first but I left my fluid evacuator at the shop.

Looked at identifix for some insight and found nothing applicable.

Currently I'm at a loss.

I'm going to take the RR parking brake cable loose of the lever this weekend and retest.

If anyone has any ideas here I would appreciate the help.

When you replaced the rear pads, did you screw in the piston to retract it all the way? You have to have the notch in the caliper piston lined up correctly to fit the pads.

 

[Superspirit]

Replace the brake hose. It's holding pressure. You can test this by unbolting from caliper and see if drag goes away

 

[airline tech]

Possibles:
***Collapsed Brake Hose - not returning the fluid
Forced piston back in = Screwed in - and in proper position (resting)? There is an alignment mark on the caliper for this, and it provides proper positioning for the inner pad (nubs)
Brake pads in correct position (Inner & Outer)? - Squeal Tab on I/B Pad and on the bottom as they are LH & RH specific
Binding on the (sliders)


Park Brake (caliper) Lever sticking

When you release the parking brake - does the parking brake lever (caliper) release fully? compare it to the driver's side these are known to hang up

 

[69/19Ranger]

Replace the brake hose. It's holding pressure. You can test this by unbolting from value and see if drag goes away

First test I did was residual pressure release.
Did not find any pressure

 

[69/19Ranger]

Possibles:
***Collapsed Brake Hose - not returning the fluid
Forced piston back in = Screwed in - and in proper position (resting)? There is an alignment mark on the caliper for this, and it provides proper positioning for the inner pad (nubs)
Brake pads in correct position (Inner & Outer)? - Squeal Tab on I/B Pad and on the bottom as they are LH & RH specific
Binding on the (sliders)


Park Brake (caliper) Lever sticking

When you release the parking brake - does the parking brake lever (caliper) release fully? compare it to the driver's side these are known to hang up

I did check the piston position pad interface. When I first pulled it apart after discovering problem it was incorrect but I made certain it was correct at each go round. At first I thought this would be the problem but it made no difference.
Before installing new caliper I made sure it was correct.

As far as pad position I looked very carefully and there were no markings to indicate L/R or inside outside. I will recheck this weekend.

Usually when thus us a concern they are either clearly marked or the pads are noticeably different.

I did not buy OEM replacement pads. I always use powerstop pads on my personal vehicles.

 

[ControlNode]

Perhaps try the ABS module bleed procedure through Forscan as a last thing before replacing the caliper/hoses.

 

[airline tech]

Then if you have the bleeder screw open and it still - drags - it's internal to the caliper and I highly suspect the park brake lever is not fully retracting - holding the piston against the rotor

 

[airline tech]

I cannot locate where I posted this - Quick Ref, so here it is again

The most important is that the (Inner Pad) knub sits in the recess of the piston and the squealer is (at the bottom) when installed.

 

[69/19Ranger]

I am sort of suspecting the same however I already replaced the caliper with fomoco new caliper and symptoms are exactly the same.

This weekend I am going to remove the cable from the p-brake lever completely and see if that changes anything.

I am also going to recheck the slider pins but there too I inspected and lubed it exactly as the LHS which has no issue.

I'm going to take it at lunch today and do a few hard panic stops and see if that changes anything.

 

[landiscarrier]

When you replaced the rear pads, did you screw in the piston to retract it all the way? You have to have the notch in the caliper piston lined up correctly to fit the pads.

This is the correct answer. I had the exact problem the OP is stating and it was the pad pins not lining up exactly the way they need to on the caliper.

 

[NotBudule2]

Back in the day,(mid/late 80's) Cadillac had some sticky rears for caliper reasons and we noticed after the repair most came back shortly after with axle seal leaks due to the heat ... just in case you needed something else to worry about ...

 

[69/19Ranger]

This is the correct answer. I had the exact problem the OP is stating and it was the pad pins not lining up exactly the way they need to on the caliper.

 

[69/19Ranger]

I cannot locate where I posted this - Quick Ref, so here it is again

The most important is that the (Inner Pad) knub sits in the recess of the piston and the squealer is (at the bottom) when installed.

Went out there and looked at it.
I swapped the pads inside/outside.

How I did not figure this on my own, I don't get.

Anyways

Thank you

Gonna swap em Saturday morning

 

[69/19Ranger]

Airline tech was correct.

I swapped the inner and outer pads.

Dammit. Wasted $150 I can't get back. So that sucks

Thank you to Airline Tech

Thank you to everyone who responded.

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