Clutch bleeding question

[keola27]

I bought "Hydraulic Clutch Fluid" and the reservoir cap says to use "dot 3".

I hear that the compounds should be the same except hydraulic clutch fluid is not rated for high heat like dot3 is.

Would i be able to use my Hydraulic clutch fluid? or is it as good as garbage.

 

[black_demon69]

I bought "Hydraulic Clutch Fluid" and the reservoir cap says to use "dot 3".

I hear that the compounds should be the same except hydraulic clutch fluid is not rated for high heat like dot3 is.

Would i be able to use my Hydraulic clutch fluid? or is it as good as garbage.

use dot 3 brake fluid

hydraulic fluid will probably cause premature failure

 

[keola27]

talked to chemist

Interesting, Talked to a bunch of very knowledgeable people.

The compound for "hydraulic clutch fluid" and break fluid are exactly the same. Break Fluid has additives to resist heat (lower boiling point)

Dot 3 having the safest additive (Glycol Ether) is generally accepted as clutch fluid.

"Clutch fluid" has no additives to reduce heat and thus on a DOT specification.

"hydraulic fluid" can be very very corrosive for automotive parts and should never be used unless i own a tow truck.

My chemist contact does not believe that glycol ether should negatively effect my seals or clutch performance in anyway.

This is a project truck at this point i don't mind taking one for the team in the name of science.

 

[adsm08]

You actually bothered to call a chemist and ask if the stuff that the manufacturer says to use is safe to use?

 

[keola27]

I didn't mean for that to be rude at all! I didn't know the manufacture said its safe to use.

I thought I would post my information here in case anyone else was wondering by.

Hes a chemist for the oil industry, and a friend from college.
He may have said they were both Glycol Ether, don't quote me on that... I don't really know.
He thought it would be perfectly safe because "dot 3" is specifically a rating for heat. So hydraulic clutch fluid can always be used in place of DOT3 in non heat specific situations. He suggested that its possible that an additive in dot 3 might have issues with a clutch hydraulic system so if it were to state "clutch hydraulic fluid only" I should not add DOT3, but he didn't think that should exist and if it did it would be very rare.

I am by no means a mechanic by trade or anything close, In-fact i am hardware and software engineer. I bought this truck to learn mechanics and decided to start with a transmission rebuild. its really fascinating how all the bits work!

I think this industry is very fascinating. example: everyone recommends ATF for the transmission when i should be using "gear oil". said chemist told me i likely have brass synchros and its easier to recommend ATF rather then gear oil because people might buy GL-5 and that would be very bad. The GL-4 Gear oil made a huge difference!
Looking in retrospect it was this site (not able to cite) that also said that ATF gear oil thing. so i decided to join.

Anyways this is all a lot of fun. Thank you for everyone on this forum!

 

[black_demon69]

I think this industry is very fascinating. example: everyone recommends ATF for the transmission when i should be using "gear oil". said chemist told me i likely have brass synchros and its easier to recommend ATF rather then gear oil because people might buy GL-5 and that would be very bad. The GL-4 Gear oil made a huge difference!
Looking in retrospect it was this site (not able to cite) that also said that ATF gear oil thing. so i decided to join.

Anyways this is all a lot of fun. Thank you for everyone on this forum!

i drained the atf and went to a gl4 rated mtf and it makes a huge difference

 

[Spott]

I recommend you look in the manual and use the chemicals that meet the specifications listed there. Then you'll never have to wonder or worry.

If the manual says DOT3, there may be a really good reason for it. If it says Type F ATF, or 90w gear oil, you should probably do what it says.

The manufacturers don't recommend things that will damage the vehicle, nor do they put in excessive requirements just to make things more complicated or expensive.