Clutch hydraulics problems and questions...

[lil_Blue_Ford]

So my primary concern is with my F-150 but since the hydraulics are very similar to the RBV, I figured it was worth posting here. Plus I'm concerned about they hydraulics in my choptop...

Back a few years ago I put a new clutch in my 1995 F-150. The truck supposedly had 69k miles on it when I got it and somewhere around 70-71k miles the clutch went out. The stock slave cylinder appeared to be in excellent condition, but since it was internal (like RBVs), I decided to put a brand new one in (from Autozone). The master cylinder has made a squeaky noise when worked since I got the truck and the clip that holds the rod to the pedal is partially broken (which makes me wonder if it was replaced before I got the truck). At any rate, the new slave cylinder only lasted until the first really cold day (less than 10*F) that I drove it, then it started leaking. I nursed it along for awhile until it completely gave out on me since I didn't have a place to work on it other than a gravel driveway (originally did the work in the neighbor's garage but his bridge washed out and there is no longer access to the garage) and Autozone refused to pay for anything other than to warranty out the slave. Finally warrantied it out and replaced it this past spring and as I predicted, the first really cold day we got that I drove the truck (under 10*) and the slave began leaking.

Problem is, it's not leaking all that fast but I have virtually no pedal. I've pumped the clutch and filled it with fluid but there still isn't anything there. So I'm not sure if the problem is solely the slave or if the master is going out too. I do know that dropping the trans to change the slave is getting really old.

I'm also concerned because I had put an Autozone slave in my choptop... and I'm starting to suspect it may be leaking as well.

And I had this thought while I was rummaging through my toolbox on the F-150 in search of some brake fluid to dump in the clutch res the other day when it started leaking... What about substituting snow plow hydraulic oil for the recommended Dot-3 brake fluid? I'm no expert in hydraulics but the snow plow oil (Meyers M-1 or S.A.M equivelent) is rated to remain fluid at really cold temperatures, it can absorb moisture and prevent corrosion and it's non-corrosive (unlike brake fluid). Of course, to use it in an existing system you'd probably have to flush it out good but... any reason why it wouldn't work?

 

[lil_Blue_Ford]

Nobody has any thoughts on it?

 

[lil_Blue_Ford]

Well... my F-150 now has a ZF transmission going into it and all new clutch hydraulics.

I'd still like some input from someone on using snowplow hydro oil for the clutch system. Stuff is pretty watery, rated down to -50* and boils around 600+*, so it looks like it's rated for the temperatures.

 

[Rowdy Fitzgerald]

I don't know about the oil but I'm thinking it could be the seal in the slave cylinder just getting cold and brittle? Or the internals in general? Then when you go and depress the pedal it cracks something in it. I've never had a slave cylinder fail like that but here in Cali it typically doesn't get cold like that.


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[lil_Blue_Ford]

I don't know about the oil but I'm thinking it could be the seal in the slave cylinder just getting cold and brittle? Or the internals in general? Then when you go and depress the pedal it cracks something in it. I've never had a slave cylinder fail like that but here in Cali it typically doesn't get cold like that.


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You would think that the seals would be rated at least into the negative numbers before they'd get cold and brittle. But then again, most of the slave cylinders I've seen come from China...

 

[Rowdy Fitzgerald]

Yep! The way I figure is your brakes work right? I'm assuming you're using the same dot 3 fluid in both? If it's still fluid enough to work in the steel lines of your brakes then it should work in the plastic hydraulic clutch line.


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[lil_Blue_Ford]

Yep! The way I figure is your brakes work right? I'm assuming you're using the same dot 3 fluid in both? If it's still fluid enough to work in the steel lines of your brakes then it should work in the plastic hydraulic clutch line.


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Brakes? Who needs 'em? All except for my 88 BII are sticks....

But yea, I hear ya. You would think that if the brakes work, the clutch should work without blowing out the seals.