Brakes

[Joeype70]

Hi all,

I have a 79 convertible Pininfarina that i just picked up a few weeks ago. I found the brake fluid reservoir empty. I see no signs of leakage but what should be the first step i take to finding out where the fluid went or whats leaking? ect.... thank you!!!

[SP3]

fill the system and pump the hell out of it till you find the leak(s). just buy the cheapest brake fluid you can find and get on with it. you may have to do a half-assed bleed at each corner after a while. or, you may find your answer well before.

[Frog2Spider]

Joeype70
I'd suggest that you get the car up on a rack so you can look at every brake component. Check all 4 wheels. Calipers and brake lines along with all line connections. You don't mention if you had any 'pedal' (brakes) and if, or how they worked?
Use ONLY non synethic DOT 3 or 4 brake fluid. DO NOT USE SYNTHETIC !

Dave.

[Joeype70]

Thank you guys, will do and i shall see where it goes from there.

[spider2081]

Its kind of common for the master cylinder to leak. Sometimes a sign of the leak can be seen below the master cylinder on the brake booster. Other times it leaks into the brake booster. If the car has been sitting I would remove the master cylinder from the brake booster and remove the rubber dust shield and inspect for a leak.

[Joeype70]

Thank you, i will check the master out as well.

[Joeype70]

Well I pumped away and didnt notice any fluid anywhere, however none of the brake fluid has moved level wise from the reservoir . Brake pedal goes to the floor. Looks like I need to star replacing some brake parts, master, booster??

[ORFORD2004]

Did you open your 4 bleeders?

[Joeype70]

No i did not. I just pumped to see if any leaks are present. Once I open all 4 what do I do next? Do I do one at a time?

[DieselSpider]

If all the fluid has leaked out then the master cylinder will have lost its prime and wont pump any fluid. Pumping it too much without any fluid in it will damage it. You can try just opening one front and one rear bleeder for a while and wait for gravity to do the job however you need the rear axle supported so that the rear brake compensator will be open. With the body supported by jacks and the rear axle hanging off the ground it will close the brake compensator so no fluid will flow to the rear. Personally I would invest in a vacuum bleeder such as an entry level MitiVac which can be had locally for less than $50 so you can suck the brake fluid through the system.

Depending on condition you may just be best off replacing all the rubber hoses and starting fresh though. Not much sense replacing the master cylinder if the calipers are shot too and not a good idea to replace the calipers and hook them to old dirt laden rubber hoses that are flaking debris off into the system. If the fluid starts coming out like molasses at first when you open the bleeders that's a good indicator that the fluid sat in there way to long and turned corrosive compromising most of the system.

From you description so far it sounds like you bought a car that was not drive-able which has not been driven in some time so yes caution is advisable.

[Joeype70]

Thanks for the suggestion and guidance. The car sat idle for a few yrs. Was mechanically sound prior to that but definitely need to ensure this brake system is in perfect working order.

[mscafide]

The brake pads may be worn so... if you push the pistons back into the calipers, in turn the fluid will go back to the reservoir. Perhaps enough to save a lot of work because it will fill the master cylinder on the way back.

Mike

[Joeype70]

Thanks Mike, I appreciate the info.

[Joeype70]

So i loosened a front and back bleeder, nice fluid flow on the front however no flow on the rears. There is fluid in back but dosnt flow even when i pump the brake pedal. I attached a 3-16 clear hose to the front bleeder and it pumped very nice through the hose. Any suggestions what my step should be. Thanks either my my fellow Fiat buddies!!!

[Odoyle]

You have to support the rear axle on jack stands while the front wheels are on the ground. This actuates the brake compensator lever, opening the valve and allowing brake fluid to flow to rear calipers. Check compensator valve (in upper rear passenger foot well) for leaks, chances are if its OE its frozen.