clutch question ?

[kalaydjian]

I had my clutch and clutch master cylinder changed about 6000 miles ago, my clutch now seems to feel different again I looked at clutch peddle rod going in to the firewall and I saw that the rubber boot around the rod had some fluid on it is that normal I checked the fluid it was full, can anyone help thank you Alain

[Freshcut]

Well, I don't own a Lotus as of yet, but my guess is that you may have a leaking seal in the clutch master cylinder. The rubber boot you speak of should only be to keep dust and debris from getting to the internals of the MC not to retain fluid that is leaking past the seals. Like I said, I don't own a Lotus but every other car I've worked on with a hydraulic clutch system should not leak into the rubber boot if the seal is doing it's job.

Blake

[mikelr]

Look's like your clutch master needs rebuilding again, there should not be any fluid present at the dust boot where the clutch rod enters the master.
Even though you fluid level looks full, the small leakage you see tells me that you probably have gotten a small amount of air bound up in the system. This is why the clutch now feels funny to you.

[cnh1990]

If the master was scored and just the seals were replaced with a rebuild kit without checking the master the new seals could leak. Also many times fine micro air bubbles that escaped the 1st bleeding can merge to form a larger pocket of air in the system and you may need to bleed the system again.
Calvin

[lotusguy]

kalaydjian said:

I had my clutch and clutch master cylinder changed about 6000 miles ago, my clutch now seems to feel different again I looked at clutch peddle rod going in to the firewall and I saw that the rubber boot around the rod had some fluid on it is that normal I checked the fluid it was full, can anyone help thank you Alain

Hi,

There should be no fluid passing through the rear seal onto the pedal pushrod. It indicates a bad rear seal in the Master.

There are three likely causes for this. a: There was corrosion/pitting present in the MC bore when it was rebuilt which was not completely removed. In the ensuing time period, the new seal has passed this area sufficiently that it has ripped. b:Conversely, when removing the corrosion/pitting, too much material was removed from the MC bore, or was removed irregularly leaving a bore which was out of round preventing the seal from sealing equally around it's circumference. c: The seal/piston was installed improperly, you must be very careful when installing the piston to not allow it to reverse or withdraw even the slightest bit until you get the locking slipring installed or an incomplete seal may occur. Also, if the car sat for an extended period, it may also have been possible that the rear seal fixed itself to the MC bore and once used, tore again.

Since both b and c will result in near instant failure of the new Master, and since you state you've gone 6k mi. on it, I am betting that a is the culprit.

Sorry to say that the only real choices are to replace/rebuild the MC again. Happy Motoring!... Jim'85TE

>> Edited by lotusguy on Wednesday 3rd March 14:35

[lotusespritworld]

I've just done a guide on the Clutch Cylinders. Might be worth following it and getting a new master cylinder from PNM Engineering. They're only around £35 and made by Wilwood. For this price it's not worth rebuilding and risking another failure.

www.lotusespritworld.com/EMaintenance/clutch-cylinders.html

kato
Lotus Esprit World