Hello I am new here. I recently bought a 1988 RX7 FC Vert. 13B engine 1.3L etc. I’ve been having problems with my clutch pedal. When I press it down it sticks to the floor and HAS to be pulled back up. I went ahead and changed the MASTER and SLAVE cylinders and bled the system. I seemed to have regained pressure back into the system but I’m still having to need to pull the clutch pedal back up from the floor as it’s still not returning on its own.

I just got back inside from working on her reading up on the repair manual and thinking maybe its the return spring inside the Slave cylinder. If not that then it maybe be a bad clutch line and fluid hose all together?

This also might be important too but when I hook up my Motive Power Bleeder to the Master cylinder reservoir and build up about 10 psi, I hear a hissing from the reservoir. Like I said its BRAND NEW replaced so unless I may have cracked something during replacement or it could be the clutch fluid hose/line that needs to be replaced itself. Thoughts?

 

If there is pressure that you can feel when pressing the pedal down and it does NOT return when released, I would suspect the Pressure Plate or Release Bearing being damaged. For 86-88 N/A, the Spring Pressure is around 1200 pounds if memory serves. Between the hydraulics, the clutch fork and the clutch pedal all acting as levers, the amount of pedal force needed is considerably less. But at the end of the day, it's the Pressure Plate that makes the pedal pop back up.

If your hydraulics had a defect in them, there would be a visible fluid leak at 10psi. Just pressing the pedal imparts considerably more pressure on the system since the hydraulics, plus the pedal and clutch fork have to overcome 1200+ pounds of force together.

 

What is your method for bleeding?

 

I use the Motive Products Power Bleeder. I twist provided cap with the tube onto the Master Clutch Reservoir and pump up to about 10-15 psi. I then put a clear hose over the Slave Cylinder bleeder valve then loosen allowing fluid to flow. (other end of tube is in container with about 2 inches of brake fluid.) Yes my clutch pedal is already being pushed down as I loosen the bleeder, then when I get a solid stream of fluid I then close the bleeder valve and bring the clutch pedal back up. I repeated this process quite a few times. I noticed a big difference from before because I actually feel PRESSURE in the clutch when I push it down. The ONLY problem is that it doesn’t return to it’s normal position, I have to pull it and bring it back to its regular position with my hands

 

welcome to the board.

pay attention the above responses!

to that, i will also add these thoughts:
1. the line should leak visibly if it were bad, but it still wouldn't hurt to change it since you basically refreshed the rest of the hydraulic system around it. (Mazdatrix has a stainless/Teflon braided one. it's nice)
2. it would not be the first time that someone had received defective "new" parts. don't condemn the parts just yet though, be sure to examine ALL other possibilities first.
3. be sure that they did not sell you the T2 slave cylinder (through mistake or ignorance) because they are different, and using the T2 slave can cause the problem you are having.

 

Thank you!! I’ll be looking into buying a new stock clutch kit which comes with a
Pressure Plate
Clutch Disc
Throw out bearing (is this same as Release Bearing?)
Pilot Bearing & Seal

from Atkins Rotary and replacing all those parts sometime soon. I will update when I can!!

 

1. The guy I bought it from said it already had a brand new Slave Cylinder and it looked like the Slave Hose that connects to the Slave itself and the hardline on the firewall was brand new (it’s a fairly new silver beaded hose from the looks) ever though he said it (slave cyl) was new I decided to buy another replacement since it was cheap. On top of that I don’t see any visible major leaks on the lines so I think we’re good on that end

3. and I apologize for my ignorance but whats a T2 slave cylinder? I added my vehicle to the advanced auto parts filter and picked which fit my vehicle. Ended up with a Duralast Slave Cylinder, part #12207 **view image**

 

T2 is shorthand for Turbo II.

the T2s used a different tranny from the N/A cars, and as such a different slave. however, they will physically bolt up to either tranny even though they are different. that said, i checked their website with the part number in your photo and you have the right one. they listed the T2 Duralast part as CS2131.

 

okay I understand. I appreciate the insight!!

 

Check your lines and make sure theyre all tight. I would try rebleeding before looking into defective parts.

When using the power bleeder you shouldn't have to do anything to the pedal. Just leave it in the normal position, attach the bleeder tube to the bleeder nipple, loosen it and start pumping. Make sure when you tighten the nipple that you are in MID-PUMP to eliminate any chance of air getting sucked back in.

 

A SpeedBleeder makes the job a LOT easier. Just be aware that while OE Mazda Slave Cylinders are normally M7x1.0 thread, aftermarket ones could be this or M8x1.0. I've seen both, so measure first, then buy.