intermittent brake pedal pulse
 

Hello,

Just had a shop replace some rear brake parts mainly the cylinders drums and shoes. Previously the cyclinders were leaking pretty bad, and brake fluid was all over the inside of the drums. Im not even sure the brakes were working previously.

Upon driving home, i noticed that the brake pedal pulses intermittently.

Its hard to predict when, and why. I assume they bled the brakes however im wondering if Air in the system would cause such a pulse.

I don't think the rear drums are eccentric because if i yank on the e brake handle while rolling it slows smoothly. I assume the rear drums and shoes are installed correctly also. I did contact the shop, i will find time this week to bring the truck to them also.

My front brake system was not touched, and it was not pulsing before. I do have the LSPV installed, and my truck is stock height. I assume it works, I assume they bled it also.

Furthermore, I would like to know the bleeding sequence inclusive of the LSPV. Is it, Furthest first, closest last, then LSPV? or LSPV first.

Don't assume. Best to see for yourself.
The rear brakes are not that difficult to do. Just need a couple of special tools. I improvised without any special tools - just a pair of Vise-grips, and I was fine.
If you could not do it yourself, trust the mech BUT WATCH WHAT HE'S DOING.

Cheap out of round drum/s.

Good call!

[QUOTE=richiethomson;52421801] i noticed that the brake pedal pulses intermittently.

Its hard to predict when, and why. I assume they bled the brakes however im wondering if Air in the system would cause such a pulse.

I don't think the rear drums are eccentric because if i yank on the e brake handle while rolling it slows smoothly. I assume the rear drums and shoes are installed correctly also. I did contact the shop, i will find time this week to bring the truck to them also.

My front brake system was not touched, and it was not pulsing before. QUOTE]

It is good to see that you tried the parking brake, this applies only the rear brakes, so if there is no pulsation your rear brakes are not the cause, as long as you applied it hard enough to really tell.
you say it is intermittent, so that makes things a little harder to diagnose, but you should really check for a dragging brake on any of the 4 corners. if one is heating up and warping the rotor or drum it could cause the pulsation and (in very rare cases) go back to normal when cool. if it wasn't doing it before make sure they check for proper rear brake adjustment and check for heat after driving, one hot and one not is a bad sign, but a little bit of heat is expected.

No, air in the brake lines will NOT cause a pulsation, just bad pedal feel and poor brake operation.