88 SR5 V6 4x4 Clutch Woes

I have a 88 SR5 4 x 4 with the 3.0 liter V6 in it. Recently, I found that my clutch pedal was sticking to the floor once engage. I inspected the master cylinder and the slave cylinder and found that both needed to be replaced. The master would not hold any fluid what so ever and the slave looked as if it had worked beyond its agreement with the master cylinder. I replaced both of them myself with rebuilt ones that I obtained from a famous auto parts store. The R&R on both of those took me about 2 hours even though I have never done anything like that. During the process of pouring fluid into the master reservoir the cardboard top, that sets on the bottle of the brake fluid bottle came off and fell inside the reservoir. I did not see this happen. After about 10 hours of banging my head against the wall as to why I could not get any pressure in the system, I finally started to check the system for leaks. As my luck (or lack of it) played, the inside of the reservoir was the last place I looked. Once I found this trash inside the reservoir I removed it, and within 5 minutes I had a working clutch system.

No one could tell me to look there in the reservoir for something blocking the flow the of the fluid. But the symptoms where obvious that something was not allowing the fluid to flow all the way through the system to the slave cylinder.

Every thing was great for a couple of days until somehow air got back into the system which left me with a spongy / sticky feeling clutch. I bleed the system once more to satisfactory pressure retention in the system. Again that service lasted only a few more days.

There most be a leak somewhere. But where? I have checked all the clutch lines, including those two rubber hose sections. They all seem fine, but do show signs of wear. One of the rubber hoses where it connects to lower portion of the metal line that gos into the slave cylinder looks a little odd. But it does not leak in my test.

Regarding that section of the rubber hose I am trying to figure out how the system works. I am not a mechanic, but I am a engineer. I wonder if once the system comes up to pressure, i.e, using the clutch to shift the gears in city driving, that the hose can no longer handle the pressure and it starts to leak out. How do these things work?

I mention this as there is a leak. I get fluid on the driveway after I have been using the clutch while driving the truck for a while. If I just start up the truck and leave it running, I get no fluid coming out. It is difficult to tell, if it is hydraulic fluid or oil as the transmission is covered in both. I spent 100.00 on paying someone to pressure wash it for me under there and to have them try to find a leak. They put in a new bolt, but the leak is still there.

Could this mean, that my rear main seal is gone? If so, does that have any relationship to the way my clutch system loses pressure. Or could it mean that I have a leak in the power steering unit? What else could be leaking.

I have had this truck since it was new I had to replace the engine about 3 years ago do to a head gasket failure. At that time, my mechanic replaced, the water pump, clutch, through out bearing, etc. I use the truck on the farm so it does have some value to me. I pull a two thousand pound trailer with it on occasion loaded with 1000 pounds of livestock. Never very far and on flat farm roads only.

What do you folks think the problem is?

Reply to
sheepdogtrail
Loading thread data ...

Just my thoughts, if you replaced both the MC and the SC, then then only thing that I can see might be leaking is at the tubing connectors, or a hole in the tubing itself. The only other thing I can think of right off is that I never buy rebuilt parts, half the time they are in no better shape than what you took off. Trace the leak, if it is coming down from the firewall area, it is the plunger seal on the rebuilt MC. if is in the area of the SC, then it is bad. Hydraulic or brake fluid has a distinct oder, unlike motor oil, sniff the can or bottle. JMTCW (1999 TACO 4x4 SR5 that beendown to the bottom of the GC)

Reply to
Joseph Myers

First, is the fluid level in the clutch resevoir going down? If so, then you probably do have a leak and the fluid on the driveway is hydraulic fluid. I suspect, however, that the fluid level is staying constant or has just gone down a little. Therefore, the leak on the driveway is something else, possibly the rear seal as you propose.

The loss of hydraulic pressure, then, is due to an internal leak in either the slave cylinder or, much more likely, the master cylinder. If the rebulid only replaced the internal seals on the old piston and did not thoroughly hone the bore, the seal can easily fail again. Fluid gets past the seal into another part of the cylinder. Bleeding will help initially but eventually won't help anymore. There is no hydraulic pressure and no external leak. All you can do is replace the master cylinder. It might be wise to replace the rubber hoses too if you have doubts about them. They can deteriorate internally and release bits of rubber into the fluid which hastens system failure. The rubber hoses are necessary to permit flexibility in the fluid line in order to allow relative motion between the drive train, to which the clutch is attached, and the vehicle body, to which the master cylinder is attached. Good luck. Al

Reply to
al

You got a crappy clutch master cylinder. Take it off and get another one OR better yet, get a better known brand.

In the past I have had a LOT of trouble with Autozone master cylinders and will not ever use them again.

Typically I do my own rebuilds but if the parts are badly worn or the rebuild kit is the same or more than the rebuilt part, I'll go with the rebuild.

-SP

snipped-for-privacy@aol.com wrote:

Reply to
Speedy Pete

MotorsForum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.