Clutch pedal drops to floor time passes I pull it back up

ford
f150

#1

So this has happened a few times pedal drops with no back pressure then give a bit pull it back up by hand and it’s fine has happened 4 or so times in the last year. I’m reluctant to replace slave and master cylinders could it be anything else? 87 Ford F-150 hydraulic clutch


#2

Usually there’s a spring attached to the clutch [edit:corrected] pedal linkage.
Either that’s broken or the problem is in the master cylinder.
At near 30 years old you’ve gotten your money’s worth out of the master and slave cyls.
In the future flush the fluid (brake fluid too) every 3 years.


#3

This is the clutch pedal not the brake
Thanks


#4

What you describe is classic clutch master cylinder failure. Replace them both and the rubber line while you are at it.

Waaay cheaper than a clutch and probably cheaper than the tow you will need when this fails completely.


#5

Mustangman , don’t clutch pedals also have a spring attached ?


#6

Some do, some don’t have a spring somewhere in the linkage. The clutch pressure plate spring should return the pedal, in any event. Some models have the spring for anti-rattle and some to help a full return. I’ve seen them both ways. My Mustang did not have a spring I could find, nor did my Saturn SC2. My 84 Camaro did. Not sure about the F150.


#7

I’m a little poor these days if I just replaced the master cylinder would that be foolish?


#8

I corrected my post above.


#9

If money is tight, replacing just the master cylinder and not the hose and slave is probably prudent since it will most likely resolve the problem. It is nice to be able to follow the “everything here is 30 years old so I will replace the whole system and be done with it for a while” approach, but that is not always feasible, particularly if it is your vehicle rather than your wife’s.

Besides, new parts don’t always guarantee long trouble-free operation. I replaced 20-year-old slave and master cylinders with new OEM parts, and the new master cylinder failed again two years later.


#10

Replacing the master will probably fix the problem if the slave is not leaking. If you are doing the repair yourself, sure, skip it but plan to replace it soon.

If you are paying to have it done, you would be paying for more fluid and some of the labor twice. Given that the slave is $20 at RockAuto, the additional labor would swallow that $20 and more.


#11

I replaced it today after it failed for the last time. I was unsure how to bleed it but after removing the slave and pushing the piston in all the way it worked great I guess this forced the air out of the line and out the cap of the master. thanks everyone!