snivley whiplash

iTrader: (4)

when engine is cold the clutch peddle has the normal 1 inch free play and the clutch works normally, as it warms up the peddle looses all free play and will slip if pushed really hard.

Set up is a repu 13b with 5 speed in a 84 fb, set up this way when i purchased it two weeks ago, only got a couple hundred miles on it since purchase and it always acts the same. Was told new clutch master and slave install recently. Maybe pedal rod set too long holding pressure on master? kinda strange, any ideas?

Thanks all

RotaryRocket88

iTrader: (7)

A full inch of free play? That's way too much. The spec in the '85 FSM is only 0.02 to 0.12 inches. Adjust the play, then see how it feels.

Nexxussian

I had a clutch do that when it got oil on it (leaking rear seal).

Good luck, I hope it's just an adjustment as it looks like a PITA to replace the rear seal in these.

bumpstart

that will not help,, and only make the issue occur sooner
i use 1 inch dead drop , with no issue
if i use less than that ,, i have the same issue as the OP when the fluid boils or expands
( 100 F is normal here in summer )

to the OP,, you need adjust the length of the slave push rod
( you may have a turbo /NA miss-match on the slave cylinder and will require a custom rod length to compensate )
and then re-adjust for 1/2- 1 inch drop again

the issue is in the adjustment of the master so that its not over the compensation port that bleeds back to the bowl
too short a slave rod makes you over adjust the master past or over the compensation port
the change in fluid density will change the rest point of the master rod,, perhaps sealing the compensation port when hot

RotaryRocket88

iTrader: (7)

It's a really simple test adjustment that could pay off. I wouldn't jump to replacing the clutch slave and master before trying it. It's unclear whether the OP is saying the clutch slips when the car is pushed hard, or the pedal is pushed hard.

Also, if your brake fluid is boiling, it is contaminated with water. The boiling point of DOT 3 brake fluid is 401ºF, and DOT 4 is even higher. Pure brake fluid should also have nearly 0% expansion with rising temperatures. Again water contamination will change this.

Does the slave on a 1st gen have some sort of rod adjustment? It sounds like you're referring to FC parts, which do not. If the pedal/clutch rod/master/slave assembly is not mismatched, there should be no reason to assume the slave needs modifying. Standard adjustment of the pedal should be all that's necessary to ensure correct engagement/disengagement of the clutch.

bumpstart

i was referring to making his own length clutch slave rod,, as only some of the very early rx2.4 and 5 had the adjustable slave rod

also i run a custom hydraulic fluid that has no issue with absorbing moisture or shrinking the rubber components and failing with a heavy pressure plate

the issue OP's issue is with the rest position of the master rod ,,, and he has already entirely normal peddle drop
which suggests to me he needs a longer slave rod so as to return the master rod to a normal position in relation to the compensation port
while maintaining the free drop AND still getting the reach required at the slave to fetch 1st and reverse without crunch

OP you need to wind back into the cabin the master rod until to see a few threads showing through the nut under the peddle

this may now make your peddle free drop many inches
if so,, you definitely need the longer slave rod,, made from a coach bolt,, with careful attention to the rounded profile ground into each end
you make things long enough so its not quite a squeeze to seat the slave unto back onto the box and onto the studs or holes ( turbo or NA )

snivley whiplash

iTrader: (4)

ok to make the matter clear. the pedal free play is there when engine/drive train is cold. clutch works normally feels good and has no issues. As thee car warms up the free plat travel goes away to the point the pedal starts to disengage the clutch with minor movement(no free play) and still work normally and feels normal in operation. When accelerating hard at wot it will slide on the 1/2 shift and the 3/4 shift, just like riding the pedal. Being the p.o. installed the new master and slave I will go back to step one and check the master push rod adjustment first as suggested. I do not think an adjustable rod is needed on the slave as I have never had to mod one on a 1st gen before and have done 4 speed and 5 speed swaps before and never had any problems, but that was me doing my own work.

I will check everything this week end and post the results. Never had any problems with 13b/ 5 speed installs before, but I was dealing in repu not rx7. thanks for the info/ insight guys, some times we get tunnel vision and need to look outside the box.

project in the works

snivley whiplash

iTrader: (4)

well I adjusted the pedal free play when is was hot after driving it for a while. Found the push rod was depressing the master in about 1/2 inch. backed the rod off to 1/2 inch free play, clutch feels much better, but still slips when hard on the throttle 1st to 2nd shift. looks like a new clutch is in order soon.
thanks guys for the help.
Joe

rosa

Hopefully you have fixed this if not have you considered the clutch itself? Depends on type of clutch and I haven't time to study possibilities.