Brake booster (hydraulic), master cylinder (1993 Chevy P30,1995 Fleetwood Flair)

The friendliest place on the web for anyone with an RV or an interest in RVing!
If you have answers, please help by responding to the unanswered posts.

Racer-X-

Member
Joined
Apr 28, 2019
Posts
6
The brakes on this thing are on my "do list." They were scary to drive with. Barely adequate to bring it to a stop, definitely no such thing as an "Emergency stop" within possibility. We drove it home from the previous owner on mostly empty roads on a weekend, and I still felt somewhat unsafe.

Looking at the system, I'm seeing the hydraulic brake booster is leaking fluid (power steering fluid) fairly profusely. It "marks its spot" when you park it. I haven't dug into the brake lines and master cylinder yet. The pedal required a lot of force (like the booster wasn't boosting), and still felt kind of spongey (like there's air in the system or maybe a fluid leak). It's getting a new or rebuilt booster and master cylinder at this point.

Has anyone used Prior Brake Products? That's the rebuilders/service that RockAuto.com offers for these hydraulic booster units and master cylinders. It looks like they want ~$160 for "return and rebuild service" for the hydro booster only, and ~$190 for the same "return and rebuild service" for the booster and master cylinder together. If I understand the process, you send yours in, they replace seals, test and fix anything else and send your exact unit back "remanufactured."

It looks like I need to know a RPO code and/or a "pedal rod code" when I order/send the unit in. RPO codes brings up another interesting question. Where is the SPIDS on this chassis? It's usually in the glove box on most GM Vehicles. I haven't found a glove box in this one, so I don't know where they might have stuck the sticker.
 

Racer-X-

Member
Joined
Apr 28, 2019
Posts
6
Sorry for the late update here.

I know it's been a while, but here's the report.  I finally got back to this project in mid August. We sent the old master cylinder, hydro booster, and the pedal linkage/bell crank piece as an assembly to Prior for rebuilding at the end of July.  They took a little over 2 weeks to get it back to us (including shipping from Atlanta to Prior in TX and back, which accounted for about 6 days total).

They seemed to do a good job. No more leaks, no more sinking pedal. It seems like they even lubricated the pivot shaft on that big bell crank for us. I took that apart to put some fresh grease in, but it looked like it was freshly greased when I pulled it apart.

Unfortunately, the pedal effort was still very high, but steering effort is also pretty high as well. We took it out anyway for the weekend before labor day, and it drove OK, but it took a lot of pressure on the brake pedal to get the thing stopped. Since the steering is also very high effort, especially at lower speeds, the power steering pump is suspect for sure.  I called Prior and they said they would take it back and take a look at it, but they recommended dealing with the power steering pump first, and if that doesn't work, they say they will take care of it.

I've ordered a new power (remanufactured AC Delco unit) steering pump (and new belts) that should be delivered today or tomorrow. I'll probably get back to it on Monday to install it. Today I'm removing the old power steering pump today. Other than the normal close quarters stuff you get with any engine work on an RV/Van, it seems to be coming out OK.
 

TheBar

Well-known member
Joined
Jun 25, 2018
Posts
1,283
Location
MS
If the new power steering pump doesn't make the steering easier have the front end aligned. If the camber angle is off it can increase steering effort. On older vehicles like mine the springs sag over the years which affects camber. Camber is adjustable on most older vehicles.
 
Top Bottom