memoir

Hi All,
New here and asking a question for a friend of mine who's not as technically savvy. He has an 87 ford f150 and he's having brake problems. This is what he's emailed me:

I've replaced the front calipers, pads, hoses, power booster- set rod to factory spec. replaced master cylinder and bled lines. no pedal height . found leak in reducer unsure of the parts name that contains two springs and several other broken pieces. unable to find any pictures on a parts list. I view it as a restrictor or check valve . the question is what is this part called for replacement and how do I finish the procedure ?

Any help would be great!
Thanks in advance.

wde3477

Welcome to the site!

Where is this reducer-thing? If it screws into the master cylinder, between the cylinder and the brake line - I'm guessing that it's the proportioning valve.

The Chilton's manual also describes a 'pressure differential valve' that screws into the master cylinder, but has electrical leads - however, I don't recall seeing this doo-dad on mine.

Tried to replace the proportioning valve when I replaced the master cylinder - however, couldn't find one, suspect it might be a dealer-only part - or that I didn't do a very good job with scrounging around.

ymeski56

Might you be talking about the ABS Valve,below Mstr/Cylndr on inside Drvr/side framerail? It's got two internal contact actuation switches. If the seals go,no break pedal & fries internal switches.

memoir

It's actually on the mast cylinder on the side closer to the cab - ours is kind of brass looking. I think you're right in that it's a proportioning valve. We went to the junk yard yesterday and found an 87 f150 and a 97 f150. The 87 didn't have this piece, but the 97 did. We got it off there and replaced ours with it and after increasing the length of the actuator rod about a 1/4 inch in addition with this new proportioning valve, we seemed to have some brakes.

Problem is, it was late and we didn't have time to test them thoroughly - so we're thinking we might need to back off the rod a bit - but aside from that, we're fairly certain we've got it.

Thanks for taking the time to respond and thanks for the information!!

ymeski56

Rod seldom reqs. adj.bet u end back w/orig adjust. Block w/wheels off ground shrtn rod only if brake drag apparent when wheels manually rotated w/trans in neutral & only amount req'd to eliminate drag. Any leaks in vac sys. will cause some level of compromise in brake performance, also, if the 1-way check valve located inside the vac hose from the booster malfunctions.