Strange Power Master problem

[Rayk]

My Power Master was intermittingly going out several months ago. Classic problem...........pedal would go to the floor and no brakes! I could turn the motor off and wait a few minutes and when I start the motor again brakes would be back.

Took the car last month to KDK Automotive, our local TR expert in Orlando. Kevin replaced both the accumulator and the switch. Problem seemed to be fixed for about two weeks. Now, problem is back. I'll start the car up and the pedal goes to the floor. Drive (very carefully) a few blocks and, all of a sudden the brakes are back to normal. The fuse has never blown and I see no brake warning light when the brakes go out.

I'm familiar with the two conversion fixes but, really want to keep the stock Power Master. So, what's the next step in the troubleshooting? If I need a new motor or master cylinder where can they be obtained? And, is it likely that something has caused the accumulator to go out again to the tune of another $300?

 

[BEATAV8]

Replace the internal seals with a seal kit from RCG

 

[Rayk]

Replace the internal seals with a seal kit from RCG

Who is RCG?

 

[pacecarta]

richard clark garage , north carolina
and get the powermaster book from him

 

[BEATAV8]

Who is RCG?

https://m.facebook.com/RichardClarksGarage/

 

[wdxwrx]

Sounds to me the problem is with the hydraulic brake portion of the master, not the booster portion. Generally, if the booster portion fails, the brake pedal is hard (no assist). The kit from RCG (if it's the same one Kirban sold), does not include the seals for the brake portion of the PM. As pacecarta said, buy Richard Clark's PM book. It's very well written. I've rebuilt a few PMs using his manual. I learned a lot. Now that I completely understand how the system works, proper diagnosis is actually fairly easy. The key is understanding how the entire Power Master works. It's actually a relatively simple system.

 

[pacecarta]

the kent moore dealer pressure gauge setup also helps to diagnose proper operation of pump and pressure switch

agree a falling pedal is usually the master cylinder portion and there are no rebuild kits to fix , all you do is clean it