Pulseing Brake Pedal

[lumbee1]

I like all the high tech brake bedding chatter. It's all true and good info. but I'd bet the farm that you have a sticky caliper. Before you jump off the cliff and buy an expensive set of racing brakes for your tractor just to destroy them in short order with a bad caliper, do inspect the old pads for wear with an eye for uneven wear. These trucks are 20+years old. Calipers do freeze up and your symptoms are EXACTLY the same as mine were. My problems were totally fixed with a caliper rebuild and a regular set of pads.

That is an excellent point. Look at your pads and compare the left and right sides for the front and then then the same for the rear. The pads should look almost identical. I had a sticky rear caliper that was causing squeal and lots of heat.

 

[NC LX]

I like all the high tech brake bedding chatter. It's all true and good info. Before you jump off the cliff and buy an expensive set of racing brakes for your tractor just to destroy them in short order with a bad caliper, do inspect the old pads for wear with an eye for uneven wear. These trucks are 20+years old. Calipers do freeze up. A bad caliper will ruin a fancy set of EBC pads just as quickly as a $40 set from Vadozone. Your symptoms are EXACTLY the same as mine were. My problems were totally fixed with a caliper rebuild and a regular set of pads.

Great point. Ill definitely be doing a inspection of everything , brake fluid flush, etc. before I put any new parts on it.

 

[JohnVee]

Lexus told me that Sarah's IS200T's brakes squeal because she has the F-Sport, which has "racing pads". After reading the above comments, I'm likely to believe their theory.

 

[roadstr6]

To inspect for a sticking caliper on multiple piston calipers, look at both the inner and outer pads on the same wheel. If the inner pad is more worn than the outer or vice versa, you may have a sticky piston in that caliper. On an 80, the front calipers have four pistons...two pistons on each side of the rotor (rears are just one piston on the inside). If, on a multiple piston set-up, you have a sticky piston on one side of the rotor and not on the other, the good side will "outpush" the bad side. When the force applied to both sides of the rotor is not equal, it becomes a break pad shoving match and rotor will get forced sideways toward the weaker side of the caliper every time the brakes are applied. The rotors don't like this and they will tell you so...especially in a 70-0 stop situation.

Also check the bolts that the caliper "floats" on. Those can rust up and not allow the caliper to move side to side as it should. Same goes for the pins the pads ride on. Wire brush, brakleen and a dab of hi temp grease goes long way toward keeping everything running smooth.

 

[NC LX]

Just a quick update, Last Friday I finally got a chance to take a look and see whats going on. Big thank you to @Green Hell Mustang and @GLTHFJ60 for helping me look it over. It's comforting knowing that there others as crazy as me to work on a cruiser even when its 24°F

The previous rotors I had were confirmed they were Warped. My guess would be due to uneven pressure applied to the each caliper piston.

Current findings were a combination of things:

• Stuck piston in the calipers on the both sides
• Improper bedding.
• Pad material transferred unevenly.
• Pad Imprinting

New parts to be installed:

• Driver and Passenger Beck/Arnley Calipers
• EBC 6000 Green Pads
• Slee's SS brake lines (7)
• Aisin Master Cylinder
• New Dot4 Brake fluid.
• Machined Rotors

The rears were inspected and wearing smooth.

 

[jfz80]

Another complete system overhaul; i like the way you work and im sure Frank does too

if you havent purchased already ive put on a few sets of NAPA calipers that have the same stamping and suspected re use of OE calipers. Nothing to be said of rebuild quality but I have had good luck.

 

[NC LX]

Passenger Side Pad

Passenger Side Caliper

Passenger side Rotor

Driver Side Rotor with visible pad imprinting.