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Hydraulic Fluid

MattP

Jedi Knight
Offline
I am about to embark on rebuilding the clutch system. I was wondering what exactly is the deal with DOT 3 and DOT 4? Also what about the synthetics can I use them or not? They say that they exeed both 3 and 4 standards, what does that mean?
 
Basically the difference is boiling point. Use what you like in the clutch. Someone is going to jump in here soon with all sorts of horror stories; for sure the old wive's tail about using only Girling fluid, but that applies only to natural rubber, and there has not been any of that used since the mid 50s. You can use synthetic if you really want to spend the money, but don't mix.
(May be a neighbor soon; going up next week to look at real estate in Fayetteville, FtSm, and VanB.)
 
Oh no! Not another brake fluid thread! /ubbthreads/images/graemlins/frown.gif Listen to Paul, he knows whereof he speaks.
 
[ QUOTE ]
Basically the difference is boiling point. Use what you like in the clutch. Someone is going to jump in here soon with all sorts of horror stories; for sure the old wive's tail about using only Girling fluid, but that applies only to natural rubber, and there has not been any of that used since the mid 50s. You can use synthetic if you really want to spend the money, but don't mix.
(May be a neighbor soon; going up next week to look at real estate in Fayetteville, FtSm, and VanB.)

[/ QUOTE ]

Transplanted Texan myself.(Grew up in Denison.)

There are about three nice houses in my neighborhood up for sale, if you're into older homes. There is a good neighborhood association, it's convenient to everything, and the old bungalows are neat. But the biggest selling point for me are the trees overhanging our street, really beautiful in the Fall. The neighborhood is in the process of getting on the National Historic Registry. There are already 3 or 4 Texas families on the block. Very friendly neighbors. Before we had everything off the truck, we were eating dinner with the couple next door, and have done so at least once a month since. The neighbors on the other side gave us a rose bush just today.

Message or e-mail me if you would like me to get you some numbers off the signs.
 
The problem used to be that english cars used real rubber in there seals instead of neopream like american vehicles. But now all the rubber products are made in taiwan for these english varients. But the only problem I have found with the new products that are out there is that the rubber or neopream is a lot thinner than the orginal was. This causes premature cracking and they just don't hold up well . I have been using silicone brake fluid for years and it tends to preserve the rubber better than the cheap brake fluid and it also disipates the heat better on a braking system not to mention it wont damage your paint from that accidental spill. this product is quite a bit higher but I believe it is worth it.
 
Just my $0.02, I discovered much debate over the whole silicone versus non-silicone fluid, and I'm satisfied that silicone is a good thing to use. I have been using it in both the brakes and clutch, and have had no trouble at all. It is true that it doesn't mix well with the DOT 3 or 4, so if you do decide to go that route you will need to get as much of the old out as you can.
 
Maybe it's just me but I think I'm hearing confusion in terminology here.

To me, synthetic brake fluid means a synthetic glycol fluid like Castrol SRP. Neat stuff but extremely expensive and what you're paying for is very high boiling point, meaningless in a clutch. IIRC you can mix them with DOT 3 or DOT 4, you just lose the synthetic advantage and it will act like the lower grade.

Silicone fluid, DOT 5, is a different animal. All the "normal" debate topics still apply but clutch systems are lower pressure/higher flow than brake systems so the "eternally spongy pedal" argument is different.


PC.
/ubbthreads/images/graemlins/hammer.gif
 
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