Chevrolet Repair: clutch ?, clutch master cylinder, brake master cylinder


Question
1994chevy 4x4 k2500 cheyanne(5speed)standard shift  will not go into gear. is it clutch and about what what will it cost ?  

Answer
Hello Bo,
You have successfully asked in two sentences, what the manual printers cover in a full chapter.

Could it be your clutch?   Yes. But there are several other things it could also be.

Cost? Depends on what turns out to be the real problem, and just how much of the work YOU do, or if it is all farmed out.

That truck has a hydraulic master/slave cylinder system to operate the clutch.  It could be just low on fluid. Uses regular Dot 3 brake fluid, in a small reservoir right beside the brake master cylinder under the hood.
That would be the easiest, cheapest possibility.
But if it is low on fluid, and adding fluid fixes it, you need to find out where the fluid went.
Three possibilities.
1.Slave cylinder leaking. It is down near the starter. See if there is brake fluid dripping there.
2. The line from the master cylinder to the slave cylinder is leaking. Look at it. Same thing. If it is leaking, replace it.
3.The clutch master cylinder is leaking. look at the firewall where it mounts, and again, look for brake fluid running down the firewall, or inside the firewall on the floorboard.

Another possibility is the master cylinder leaking internally back past the piston, but not leaking externally. That scenario would not necessarily be low on fluid...it could actually be full of fluid. Just not working. That possibility doesn't exist for the slave cylinder, because if IT leaks past the plunger, it will leak out.

Best way to check is to remove the little inspection plug from the clutch housing, and as someone presses the clutch pedal, see if the slave cylinder extends and retracts in there.

That's the cheap hope.
Talking maybe $45.00 range to buy all of those parts.

Now to check the clutch.
It IS a wear item, and over time, depending on how it is used, one can expect to sooner or later replace the clutch.

Replacing it requires removal of the transmission, and with a four wheel drive, it also requires removal of the transfer case.
Major driveway work, but completely do-able. You WILL learn new ways to swear, or express your frustrations, but the job can be completed there in the better part of a day, baring unforseen other problems.
So before starting it, I would make SURE the clutch is needed.

Before the current problem, did it slip when driving, like after shifting into high and maybe going up hill?
Did it smell like burnt brake lining?
Did it pull real heavy loads during its life?

If you can shift it into gear before starting the engine, put it in say second or third gear, start the engine with the clutch pedal depressed, and the brakes applied, and then let up on the clutch and see if it kills the engine, or just slips.
If it will kill the engine in third gear, the clutch itself may,(MAY..)be fine. Check the master/slave system.
If it slips, smokes, stinks,....you can remove an inspection cover down under the flywheel, and actually look at the clutch. Big hunks of clutch disc material laying in there is a bad sign.

OK...turns out to need a clutch.

Tranny etc out, bell housing removed....check the fork and pivot ball stud for excess wear. That pivot stud and fork need to be looked at while you are in there.
Remove the pressure plate and clutch.

You can get just the clutch disc if you want...but look at the pressure plate wear surface, and see if it is all cracked, or badly worn. Heat spots also.
If it has them, or even if it doesn't, look at the flywheel for the same thing. It can pe resurfaced, but even if it looks like brand new, think back to the starter operation, and if you ever had any starter grinding problems.
That is a different subject, but if you have damaged teeth on that starter ring gear, this is the time to replace it.

Assuming all that is good, check or replace the pilot bearing in the rear end of the crankshaft. That is a little thing the transmission shaft fits into, and supports the front end of it. Great time to replace that.

Normally, do all those things, plus replace the clutch disc, pressure plate, and release bearing, and you are good for another hundred thousand miles, or about the same life as the orriginal, if you continue to drive it the same way.

GM will probably want a little more than $300. for the clutch and pressure plate.
$200. for a flywheel(Guess).
$50. for a release bearing.

Several hundred for labor.

"O"Reillys price for the clutch/pressure plate kit is $109.99
Release bearing is $39. but one may be included in the clutch kit....ask.
Flywheel, if needed is $99.

Labor?? You and a friend or two, borrow or rent a transmission jack and some jack stands....case of Bud...depending on experience level of friends, and consumption rate of bud...a nice long day. Quicker without the Bud, but hey....you weren't going four wheelin anyway.

I would recommend getting a manual, or at least going to the public library, refference section, and make some copies.

Then get some estimates.

Van