QuestionQUESTION: Howard,
Sorry to bother you (again). As you may recal, I've rebuilt my slave and master cylinders, new fluid and complete bleed of the system. I drove my Triumph in to work today and it performed perfectly UNTIL I got into the parking lot. As I went to park, I had trouble getting it into 1st gear and could not get it into reverse. (7:00 AM)
I went back out at 10:30 am with a friend to try and replicate the problem. The car shifted perfectly in all gears (forward and reverse). We took it for a ride around the parking lot, and had no issues. I've parked the car and am now scratching my head.
Do you have any thoughts on what could be causing this? Any suggestions would be appreciated.
Thank you!
Vito
ANSWER: Hi Vito, If the pedal felt the same as before the only thing I can think of is that you may have a pilot bearing causing the problem. Not really enough symptoms to diagnosis. If you use the clutch too much in traffic you may be warping the disk a little.
Howard
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QUESTION: I'm really scratching my head.... when I drove it from work it started out fine, but after the first 2 miles, the clutch started acting up again... wouldn't disengage with the pedal fully pressed. Got to my location parked it for 2 hours, and when I went to leave again worked fine (again)for the first 2 miles. I should point out I only travel country roads, so very little clutch use until I get to a stop sign. One of my friends is suggesting the hydraulic line could be swelling once it gets hot, resulting in me losing hydraulic pressure to the clutch... I believe it is the original 30 year old hydraulic line. Have you ever heard this? Can heat effect the pilot bearing? How can temperature or use change the characteristics of the hydraulic clutch system?
ANSWER: Vito, you still have not responded to my statement "IF THE PEDAL FELT THE SAME". Does the pedal feel the same when it is failing????? Any hydraulic problem will make the pedal feel different and you will get different free play in the pedal. I never have seen the plastic line swell up due to heat and if it did it would not return to it's original shape like a rubber line would.
Howard
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QUESTION: Howard,
Sorry for not answering your initial question.
The pedal still feels firm, and the amount of travel before it gets firm may grow a very small amount once the car has run for 2 miles. Also, the overall feel MAY be slightly less pressure when pushing once the car has been run. It is difficult to say as the sense of urgency when it stops working makes me want to push my foot through the floor! In short, I would say pedal pressure appears to go down once the car has been run for a couple of miles and the free play may slightly increase.
AnswerI found the best way to gauge it is to hand push the pedal down when cold and run the car until it is hot and hand push the pedal again to gauge the difference if any. If it is about the same there is NOT a hydraulic problem even though that is the easy thing to repair.
Some times working in a dealership and facing a problem that may not be evident even with the parts out in your hands is a dilemma for a shop because a shop is expected to come up with a "fix" when charging for work so often a shop will require that all associated parts (clutch kit) be replaced including the pilot bearing.
I have seen different cars have a slightly dragging clutch (like you have) and the cold trans lube stops the first motion shaft from spinning the disk but after a short drive the gearbox oil warms up and the first motion shaft no longer has that "brake" of thick oil to hold it and the disk than spins and thus the crunch in reverse etc and even low gear that has a worn syncro.
These are problems facing mechanics all over and since you are now the "mechanic", you must face them and try to make decisions on what to do to correct the problem.
Another factor is the driver. I have many times working in dealerships found that a driver will have bad habits like, pulling up to a light and putting the car in neutral with a high idle (1000 RPM and up) then when he sees the light change he quickly steps on the clutch pedal and grabs low gear. Results = crunch. He says "but I do that when I start up at home and don't get a crunch!". But the thick oil in the gear box acts like a brake for the lay gear which stops the first motion shaft that the clutch disk is mounted on. When the oil is warm the clutch disk acts like a flywheel and when the clutch pedal is out the disk is spinning at engine RPM and so is EVERY gear in the gearbox. The mainshaft and ALL of the hub assemblies are stopped when the rear wheels are stopped so now he tries to make a spinning gear (Engine RPM) connect to a stationary hub. Result = Crunch. Even a good system with hot oil can get a crunch if the driver tries too quickly to put it in gear.
Here is a little test, Put the gear box in neutral and start the car cold and put it in reverse gear quickly on level ground with the brake off and just sit there a minute with the clutch down and note if the car tries to creep. Also did you get a crunch?
Now with the engine still running put it back into neutral and let the clutch out. Now depress the clutch pedal and hold it down for 5 seconds and put it in reverse again. Did you get the crunch?
Next, put the car in neutral again and put the pedal down quickly and and put the gearbox in 4th gear and then quickly put it in reverse. Did you get a crunch this time? You should not get a crunch this time.
Go to my web site and read my tech tip on gearboxs. http://mg-tri-jag.net/tech4.htm
let me know the results of each test I outlined above.
Howard
