1997 sw1 brake mysterio???

[Professor S]

Hello All!
PROGRESS on 1997 Saturn SW1 automatic,

HOORAY IT STARTED and is engine is running steady and sounds strong.

To recap it was sitting 3 years under shelter in mountain Rainforest, ran well when parked, then would crank but not start.

New fuel pump and now it starts. I drained and replaced oil and filter before starting also.

I also drained and replaced Transmission oil and filter.

Radiator is starting to corrode so I Am ordering a new one before it goes, meanwhile temp gauge working etc.

Then I noted the brake pedal went all the way to the floor. I checked the master cyl. and it was NOT low. SO I pumped the pedal about twenty times and checked again and the m/c was EMPTY!

WHERE DID IT GO?

Refilled the m/c in order to find any leaks, pumped pedal again and the m/c was EMPTIED faster than Rosanne Barr could inhale a large cheezy crust pizza AGAIN!

Got under car again and checked for leaks at wheel cylinders ot ANY evidence of leaking fluids and found nothing?

Dad retired as mechanic, we lived on rural farm, and did all our own vehicle and appliance servicing. I started on cars around 1971.

Never seen this..

ALL help is greatly appreciated.

[fetchitfido]

It's either stuck in the Vacuum booster or in the rear drums. If the engine was running during the brake test I'd say the MC failed and now the pressure booster is filling with fluid. You should be able to check by unbolting the MC from the booster and pulling it forward, if it's leaking that way that bad you'll have fluid come out as soon as it's cracked loose.

[Professor S]

Hello Again all!

Thanks Fetchitfido!

YES the engine was running during the test, BUT I also pressed the pedal after turning OFF the engine and the pedal was MUSHY with a bit of pressure. Tested again with engine on and same thing, Switched off a a gentle mushiness returned, but pedal still goes to the floor.

I never had to service pressure booster / Master cylinder items on a car, though I have been working on my own since the 1970s thereabout.

Please advise on Which items to check in which order etc. This way I can order any parts when I order the radiator.

Much thanks. God bless and be well!

[TomM96]

Prof needs determine where the fluid went drums/vac booster.

A sniff at the rear wheels might help, unless they are totally rusted shut.

So maybe loosening MC mtg bolts, and pulling unit forward would be
revealing.

Have you inspected the bottom of the floor pan; rear drag links; rear door
rocker panels, and the PowertrainCradle/forward subframe for rust
degradation?? Can be effective Go-NoGo viability project test.

I think the brake booster assemblies are available rebuilt, with new
rubber bladder, for a significant price. They usually fail after some years,
particularly in wet/corrosive environment.