Thursday, October 6, 2011

We're trying to figure out why our engagement point kept changing with our clutch. Please See Below for Story

We just had our master and slave cylinders replaced on our 93 Honda Accord clutch and over about 400 miles, the engagement point (and pedal) moved up and up to the point that the clutch no longer engaged. I was out of town and another mechanic adjusted the pedal (and engagement point?) so that I could return home (about 250 miles) and told me that my clutch was shot based on something the mechanic had done/not done. When I returned to the original mechanic, he could not find anything wrong with the clutch or the cylinders he replaced (he's done the tests recommended by the manufacturer at their direction). I have been using the car for the last few days and it has been working okay. Until we figure out what happened while I was on the road, we think it'll happen again. Any ideas??
We're trying to figure out why our engagement point kept changing with our clutch. Please See Below for Story
You don't adjust hydraulic master and slave clutches. You bleed them. What happened was when you had the clutch repaired about 400 miles ago, there was somehow an air pocket allowed to get in the system. This air pocket slowly but surely worked its way up to the master cylinder. When it made it to the master cylinder, your pedal no longer worked because when you depressed it, all you were doing was compressing the air pocket. The out of town mechanic %26quot;fixed%26quot; your clutch, he bled the system. This eliminated your air pocket, allowing the clutch to work again.



Too often, mechanic will tell you your clutch needs replace if ANYTHING goes wrong with it. Sorry, but this is a scam. A clutch has several components from where you push the pedal to where the clutch meets the flywheel. If anyone of these components fail, DESPITE what some mechanics would have you believe, then that component needs repaired or replaced, NOT the entire clutch system. The out of town guy told you this hoping you would, out of fear of complete clutch failure, tell him to replace it. This would have been more cash out of your pocket. Then, more than likely, he wouldn't have done nothing more than just what he'd already done but charged you for a new clutch.



As long as the clutch system is properly bled now, you should have no other problems. In defence of the original mechanic, it wasn't necessarily his fault either. A lot of clutch hydraulic systems, like yours, aren't supposed to need bleeding. You replace the whole sytem as a unit and run it. MOST times this is all that is needed. Every now and then though, you get a stubborn one that will need a little bleeding. This is usually caused by letting a little air in as you install the line between the master cylinder and slave cylinder. However, you never know this until usually 5-6 hundred miles later when the clutch pedal starts to get %26quot;soft%26quot;.



By the way, for future reference, if you had gone ahead and allowed the out of town mechanic to scam you, there is a little tip to prevent this that I've always advised people of (I done mechanic work thirteen years). ALWAYS, ALWAYS, ALWAYS, INSIST on getting your old parts back ANTIME a mechanic replaces ANYTHING. There are tons of shops out there that charge for replacing parts when they haven't replaced NOTHING. That is what caused me to go into business for myself. While working at a dealership, I wouldn't participate in scamming honest hard-working customers.
We're trying to figure out why our engagement point kept changing with our clutch. Please See Below for Story
My guess would be that the clutch, having less fluid to activate it, had been working its way out of adjustment, but you had not noticed it until you replaced the cylinders. Once full pressure was returned, the adjustment went out even quicker, causing falure.



What I am assuming your %26quot;temporary%26quot; mechanic said was something to the effect that the clutch should have been replaced when the cylinders had been. However, that does not always mean that the clutch is bad. If it is still working fine with the adjustment, I would just keep an eye on it in case it begins to get worse. Clutches do wear out after a while, and yours may be getting very worn, which may have aided in the cylinder going out. Continue driving it, but begin thinking that a clutch replacment %26quot;job%26quot; may be coming up in the future.
Hydraulic clutches aren't usually adjustable. The only adjustment is the height of the pedal and it doesn't really affect the clutch operation unless it is over adjusted, it would not do this on its own while driving. Sounds to me like the clutch is getting stuck or overheated.

I used to own a 300zx turbo, one day I went to go drive it, and I shifted down to go up a hill, and the clutch would not engage. I put it in neutral and pumped the clutch, and it came back and worked fine. Not sure why it did that, but I never had a problem with it after words.
Hydraulic brake and clutch systems, always always always, set themselves to the same spot by the use of a hole in the bottom of the reservoir.



When the pedal (brake or clutch) is not being depressed, the M/C piston retracts so that the fluid in the lines is in contact (via this hole) with the fluid in the reservoir. That's what the reservoir is there for, really.



Here's the problem: If this fails to happen, you may %26quot;pump up%26quot; the clutch or brakes and they won't be able to bleed back down. There are two ways this hole can fail: It can stop up, which doesn't tend to cause this problem, or it the piston can fail to retract far enough, which does cause the problem.



Since all that stuff had been taken apart recently by mechanic #1, you can be very sure that was the problem. The clutch M/C piston didn't fully retract.

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