Midget 1500 dual circuit Master Cylinder troubles

[RickB]

All the fluid leaked out from both the front and the back of my brake master cylinder. I haven't taken one of these apart in a Midget but I have rebuilt them in the MGB before. The thing is that usually it's one or the other that fails but not both front and back in my experience.

I'm thinking maybe there was moisture in there and with the cold here (8 degrees this morning) it froze and caused failure? Sound reasonable? Any thoughts?

 

[mightymidget]

Fluid contamination or wrong type of brake fluid installed

 

[RickB]

definitely not "wrong type" as I am the only person who has done any brake work on the car since I have owned it and the first job I did was flush the brake lines.
Contamination? Well this is the pacific northwest and it gets very very wet here, then cold, then hot, then cold and wet again.
I could easily believe condensation contamination.

 

[sparkydave]

Having attempted to rebuild one of those, it's a PITA. There's a thick nylon washer that probably froze to the pushrod, and getting it out without scratching the bore is tricky. Then there's a snap ring buried down deep inside that needs a long pair of snap ring pliers to remove. I got a rebuilt from Napa for about $180.

As for the failure, tough to say. If it did get very humid, things may have just gotten rusty enough inside that the seals abraded and leaked. Don't overlook the brake failure switch (PDWA) either. If you unscrew the switch from the body and fluid comes out, it may have leaked down there.

 

[JPSmit]

Having attempted to rebuild one of those, it's a PITA. There's a thick nylon washer that probably froze to the pushrod, and getting it out without scratching the bore is tricky. Then there's a snap ring buried down deep inside that needs a long pair of snap ring pliers to remove. I got a rebuilt from Napa for about $180.

not sure why it failed, but, I found it to be an easy rebuild - once I knew where those pesky things were

 

[JPSmit]

All the fluid leaked out from both the front and the back of my brake master cylinder. I haven't taken one of these apart in a Midget but I have rebuilt them in the MGB before. The thing is that usually it's one or the other that fails but not both front and back in my experience.

I'm thinking maybe there was moisture in there and with the cold here (8 degrees this morning) it froze and caused failure? Sound reasonable? Any thoughts?

sounds odd to me, partly cause that would be a fair bit of moisture but mostly because to my mind it should have pushed up into the reservoir. On the other hand, it might just have been push enough

 

[Guest]

New on ebay for $100. I'm tempted to convert to something cheaper, like VW bug.

 

[RickB]

BillM to the rescue again.
I emailed Bill at work and he said I should bring it over to his house.
Bill has a garage and a heater.

We bled all four corners and I had brakes like crazy!

I'll see how it is tomorrow morning. :wink: