Triumph Repair: cluch, clutch master cylinder, clutch pedal

Question
When i push and hold in the clutch and put car in gear its takes off on me . it doesnt wait for me to let the clutch out.

Answer
Hi Debbie,

The clutch on most Triumphs is disengaged by hydraulics, so when you push on the pedal down, it pushes a piston in a master cylinder that forces brake fluid down a pipe to a slave cylinder and in the slave cylinder is a piston that forces a rod to disengage the clutch itself.

Even though the clutch itself can fail the most common failure is in the hydraulic system. There are a few tests that you can perform yourself without any tools to diagnose the problem before you need to take it to a shop.

First go under the hood and open the top cap on the clutch master cylinder. (directly over the clutch pedal.) Use gloves or a shop rag and don't let any droplets of fluid come in contact with the paint on the car. If the fluid level is low add brake fluid and be sure to use a brake fluid that is rated "DOT-4".

If it was very low and you had to add a lot of fluid, put the cap on lightly not tight and go in and pump the clutch pedal full length strokes but in a very slow motion.

If the pedal was very soft (easy to push) most of the way down and it started to get hard to push just at the bottom and as you pump and the pedal kept getting harder to push until it was firm to push just an inch or so from the top. Then that was normal and you have for now corrected your problem and then recheck the level and fill if necessary and put the cap on tight.

However, if that fixed the problem, it most likely is just a temporary fix because the missing fluid had to go somewhere and it was a leak. First check the back of the pedal arm for signs of leaking fluid (a leaking master cylinder) and have the car put up on a lift and check the slave cylinder for leakage. (This may require that the slave cylinder be removed from the car to examine) If refilling the master cylinder and pumping up the pedal fixed the problem some people just leave a container of fluid in the trunk and check the fluid level from time to time and if it requires refilling often, then you need to find a Triumph mechanic to either rebuild the Master cylinder and slave cylinder or replace both. The reason you do both even though only one may be leaking at the time is because usually if one is bad the other is not far behind it.

If however, on the first test you found that the master cylinder fluid level was not low then you need to run a different test. Operate the clutch pedal by hand. (Engine off) You should feel free play in the first inch or so and then the pedal should be firm and hard to push by hand. You then need to force the pedal down to the floor and note how hard it is to push. It is suppose to be the same hard push all the way to the floor. If it is soft and easy to push after the first free play and it gets harder to push only when it gets close to the floor then you have air in the hydraulic system and the system needs to be bled. This usually requires two people to do.

You didn't toll me what kind of Triumph this was as some have clutch hydraulic problems from the factory. The TR-6 and the Spitfire both suffer from a lack of clutch slave cylinder travel so even when they were new the clutch would engage just off the floor and when they were new some owners would put thick nice carpet in on top of the existing carpet and that made the clutch not release completely even with the pedal all the way down. I was able to correct the problem on the later TR-6 by substituting the earlier version of the TR-6 master master cylinder which had a larger bore size which made the clutch release better. I never did research the hydraulic cylinder sizes to see if that was possible to do on the Spitfire too.

Let me know the results of these tests.

Howard