Topic: Type of Fluids

[ChrisV289]

Getting close to putting the rear end back in the car (have to now since bought a new house and the car has to move) and would like to know what fluid type people are using for the brakes and rear end.  I've read DOT 3 and 4 are OK, DOT 5 is better but is prone to moisture build up at the wheel cylinders according to an article and has a spongy feeling.  Car is seldom driven but it is taken to local shows during car show season.  Has drum brakes all around.  Also it is hot here in Phoenix but not driven during the summer months.  Also what type of gear oil should be put in the rear end?  Shop that changed out my pinion seal and pinion yoke recommended 85/140. 


Thanks,
Chris

[J_Speegle]

How do you plan on using the car would be my first question - mostly for the brake fluid part of your question.

Guess that your rearend is an open rearend - correct?

[ChrisV289]

Jeff, using the car for recreational driving to shows and back.  Maybe on the highway a little bit but not much.  Not sure what you mean by open rearend.  I still have to put the axle seals in, axles themselves in, backing plates (brake shoes, etc) back on.  Standard Ford 8 inch rear end...

[CharlesTurner]

I usually use silicone in the show cars, easier cleanup.  Only time you'd experience fade would be during extreme driving, like on a track.

[bgp429]

+ 1 on the silicone. Have been using it for 15 years without an issue. I do suck the fluid out of the master every year and replace with new.

[Smokey 15]

 Make that 3 for silicone. Every car that I change the brake system on gets it. Never had an issue. Just make sure every fitting is real tight as it will leak easier than regular fluid. Plus, it doesn't eat paint like other fluids.

[markb0729]

Not sure what you mean by open rearend.

Open rear - only one wheel spins when you apply power
Limited slip, posi, etc. - both wheels spin when you apply power

[bgp429]

Might add about dot 5.  The old dot 3-4 fluid needs to be completely gone. That is impossible unless the calipers, cylinders and master are new or fresh rebuilds. Lines flushed before cylinders and calipers are installed.  Denatured alcohol or dot 5 will work for the flush. I used a new squirt can.

[J_Speegle]

Jeff, using the car for recreational driving to shows and back.  Maybe on the highway a little bit but not much.  Not sure what you mean by open rearend.  I still have to put the axle seals in, axles themselves in, backing plates (brake shoes, etc) back on.  Standard Ford 8 inch rear end...

As markb0729 has already provided you the difference the open rearend will just use regular gear oil while the limited slip, posi .... will require and additive for the clutch packs

[67gtasanjose]

Open rear - only one wheel spins when you apply power
Limited slip, posi, etc. - both wheels spin when you apply power

(NOTE: not typical description for inline 200 six cylinder cars) 

[Anghelrestorations]

Chris,  I have to agree that DOT 5 brake fluid is the way to go.  I use it on all the cars and rebuilds I put together.  Unless you are pushing a car to the limit on the track this works great and cleans up easy. 

As for gear oil I use an 80/90W fluid which I think is what we used originally on these cars.  I look for a Brad Penn brand oil but obviously you can buy different brands locally.

Good luck on your move. 

[sgl66]

Might add about dot 5.  The old dot 3-4 fluid needs to be completely gone. That is impossible unless the calipers, cylinders and master are new or fresh rebuilds. Lines flushed before cylinders and calipers are installed.  Denatured alcohol or dot 5 will work for the flush. I used a new squirt can.

Flushing with Dot 5 is not recommended. Details about why is spelled out in one of the links below...it doesn't work is the short answer.

http://www.studebaker-info.org/text3/silicon.txt
http://www.dtic.mil/dtic/tr/fulltext/u2/a251835.pdf

Lots of other good info about the pros and cons

[Smokey 15]

 I must be the exception to that rule. We completely flushed the system on our '62 Buick with Dot5 after switching to a dual master cylinder (drum brake).