What fluid in a hydro clutch?

[RingMaster4x4]

I am about to finish my SM465 swap and need to know what fluid goes in the master cylinder. Thanks for any help.

 

[86chevybanshee]

i think u can use brake fluid

 

[readymix]

Dot 3

 

[RingMaster4x4]

Can I use one of the higher rated ones? I only ask because the slave cylinder is close to the header.

Dot 3

 

[RingMaster4x4]

Ttt

Ttt

 

[readymix]

you can go with 3 or 4. I am not sure about DOT 5 though.

I used it in the brakes for my bikes when i still had them.

 

[RingMaster4x4]

ok thanks

 

[Burt4x4]

I am going to use Dot3 in mine. I think I remember reading someone using Dot5 and all was fine. Just don't mix or forget you got Dot3 in your brakes and Dot 5 in the clutch. The main reason I am sticking with Dot3 and cost too....

Good Luck
Burt

 

[RingMaster4x4]

What temp will dot 3 withstand? The bleader is about 1/4 inch from the header. I am going to rap the slave cylinder with header wrap to help with the heat.

 

[84_Chevy_K10]

DOT 5 is not fine. Do not use DOT 5 in any of these trucks. It's nearly $30 a quart anyway.

DOT 3 and 4 are totally interchangeable for our trucks since DOT 3 is all that is required.

Just use DOT 3, it works fine and it's cheaper.

DOT 4 gives you an ever so slightly higher boiling point but it's going to get 400*+ before it boils anyway, so don't worry about it.

Clutch fluid isn't going to boil. The clutch system itself doesn't create heat like a brake system does. I wouldn't worry about it at all.

 

[K5MONSTERCHEV]

.3 Dot 3

 

[DieselSub]

There are also special fluids for clutch master cylinders.

I have a Jeep Wrangler, that after replacing the clutch master cylinder, would have a very *un* smooth feel - kind of like it was sticking as I pressed the clutch down. I replaced the master cylinder twice, all the fluid, and still the same problem.

Jeep was clueless and gave the standard dot 3 brake fluid answer, but GM has a special clutch fluid that solved my problem. If you run into this problem, give your local GM dealer a call and ask for this special clutch fluid.

 

[84_Chevy_K10]

give your local GM dealer a call and ask for this special clutch fluid.

Make sure you pick up some blinker fluid and a muffler bearing while you're there.

 

[beater_k20]

If you run into this problem, give your local GM dealer a call and ask for this special clutch fluid.

and they will hand you a bottle of DOT 3 brake fluid.

 

[DieselSub]

and they will hand you a bottle of DOT 3 brake fluid.

Laugh if you want. But I tried off-the-shelf DOT 3 in two different master cylinders for the Jeep. Each time I filled it up with DOT 3 and the clutch started to get squeaky and start binding after a week of driving. "Of course it's not the fluid, I just put new DOT 3 in".

After searching all around the net I finally found a reference to GM's fluid fixing a problem similar to mine. I tried it out, and indeed it fixed my problem. I'm guessing the seals/bore on my particular master cylinder are sub-par in some way - I got them from Kragen The GM fluid probably has greater lubricity to make up for the plastic bore.

And yes, if you go to the Jeep dealer and ask for their "special" clutch fluid, you'll probably get DOT 3 for $10 a little bottle.

 

[K5MONSTERCHEV]

Make sure you pick up some blinker fluid and a muffler bearing while you're there.

LOL, I have to agree with you here. We use brake fluid in all the clutches that come through the doors and have never had problems.