rtruman

Use dot 3 or 4 and move on to next project.

MOXIE62

I always had leaks when I used silicone fluid.

oemtech

Dot 5 is HP usage... DD's & garage queens don't need it. I hsve use the stuff from Wal Mart in my RV from 12 years. Brake flush is about $12 (3 qts) and about 30 mins with Speed Bleeders.

babbah

If you prepared the system correctly and made sure that your caliper seals were in good shape, then I don't understand how you had any leaks.

In my case in 1982, I purged the system from all DOT3 fluid, the rebuilt my stainless sleeved calipers with new seals, reassembled and bled the system.
Not a problem since and the DOT 5 fluid in my master still looks brand new today.

Joemac8

Why not 5.1?

RatDog

Joe - I have Motor Medic brand DOT5. It's made by GUNK in the USA. I got it at Amazon because I couldn't find 32 oz bottles locally.

Steve

GTOguy

Didn't bother to read ALL of the opinions posted, but didn't see the obvious addressed: if your car has sat for 4 years and is behaving as you describe, you have one or more frozen caliper pistons. A brake fluid flush and pad change isn't going to do it. You will need to remove and overhaul the calipers and go from there. I personally use DOT 3 or 4 and drive the cars as much as possible. (mechanic for 40 years). YMMV....

Bill Pilon

I have used silicon brake fluid for 30 years or more with zero problems, only normal wear on friction items.

I don't bother flushing or messing with, I figure when I get a leak I will rebuild the system and refill it with silicon fluid.

Bill

wmf62

more 'fuel' for the non-DOT5 fire....

http://www.toprateten.com/best-brake-fluid/

Bill

Joemac8

I am SO confused!!!

rtruman

Used dot 3 for 25 years no problem ,If you use dot 5.1 you have to make sure its all cleaned out

Joemac8

I am goilg to clean and flush my lines. I will also either rebuild the calipers or, if they are not SS lined, have them rebuilt. Now, with a fresh set of calipers and a flushed system, I want the best brake fluid that will work for an occasional driver that is stored in below zero temperatures for six months each year.

It is obvious that there are conflicting views on which fluid to use. That is what has me confused. How to decide? Which to choose for my application?

rtruman

I drive mine at least once every two weeks for a 8 mile ride .They will last for a long time .I used the regular dot 3 , it stops fine I have power brake booster with drum brakes , When you done use them often they have problems .
Maybe you need to take your car out drive it ,brake as you should and test it using it don't baby it if it still pulls get new replacements ,and turn the rotors if you have to .One fix and you wont have to mess with it anymore just drive it enough to keep it in shape.
Goggle the brake fluid and see what people say you will get a lot of feedback.

wmf62

I THINK you have DOT5.1 confused with 5.0; 5.1 is totally compatible with 3 & 4.

Bill

RatDog

Bill - I think that confuses a lot of folks because it makes no sense. They should have named it something else. Even 3.1 or 4.1 would have been better.

I wonder how many people figured 5.1 was just an improved version of 5 and ended up mixing it with 5.

Steve

rtruman

What I was trying to say is avoid all 5 series Brake fluid .
I don't use it on the 63 and think its overkill.

wmf62

it seems to be an anomaly; 5.0 & 5.1 only share the #5 and nothing else.

personally, I use Castrol LMA

Bill

Powershift

Based on everything I have read on this post, my recommendation to the OP is to go back with DOT 3 brake fluid, just like OEM. It is the easiest to work with and will be just fine for the car. Just remember to flush the brake fluid every 3-4 years.

I changed over to DOT 5 silicone fluid 20 years ago. Probably best thing I did for me and the car. But I started from a fresh, all new system.......everything new.........and took my time. I have been doing brakes for over 50 years so there is usually no surprises. The DOT 5 did require more attention to detail and to stop very small/minute leaks. But once done,it is DONE. Flushed the system after 18 years and it still looked like new fluid, with only slight discoloration of fluid at the calipers (maybe first 1-2 oz of flushed fluid). The rest was original clear purple color.

But with all the questions and issues and inexperience of the OP, I would just recommend DOT 3 for him.

PS: Not all DOT 3 is created equal. Prestone, Castrol etc will be fine. But the FORD DOT 3 fluid for the race track is the top tier of DOT 3 fluids. Buy it if you want the best. Otherwise stick with major brands.

Larry

GUSTO14

As has been previously mentioned all DOT 3, 4 and 5.1 fluids are glycol based fluids. The major difference between them is their boiling point. The boiling point of glycol based brake fluid is directly related to its moisture content. Since glycol based fluids absorb moisture directly from the atmosphere, the minute they are exposed to air they begin to absorb moisture. Moisture is the major source of corrosion in hydraulic brake systems, but it also lowers the boiling point. Moisture is a major reason the racers flush their brakes systems on a regular basis. On many containers of glycol based brake fluid, you will find a warning that suggests, "not to be used from an open container", and that is the reason.

One other thing to throw into the mix; DOT 3, 4 and 5.1 are all available labeled as synthetic. NOT to be confused with silicone. In fact most all DOT 3 or 4 brake fluids I've found lately are labeled synthetic. Think of it as similar relationship to conventional oil and synthetic oil. This is a good thing in that if you are going to use them, you may as well use the best type.

Corning was for quite some time considered the best source for silicone brake fluid. The Department of Defense was (and may still be) buying it in 55 gallon drums. They began switching all of their rolling stock with hydraulic brakes/clutches to silicone in the 80's. The primary reason was to reduce maintenance and increase readiness of equipment.

My preferred method of switching from glycol based fluid to silicone fluid is to start with new calipers/wheel cylinders. This alleviates the burden of trying to remove all of the glycol based fluid from an assembled caliper. With the calipers removed from the system, I disconnect the lines from the master cylinder and blow as much of the fluid as possible from them. Then remove as much fluid as possible from the master cylinder, if you are not starting with a new one, and flush it with denatured alcohol. Reconnect the lines to the master and flush additional alcohol through the lines. Once you are satisfied that clean alcohol is all that is coming from the lines introduce the silicone fluid into the master and gently pump it to each corner until only silicone fluid is coming from the lines. Reconnect the lines to the calipers bleed the brakes normally.

One drawback to silicone fluid is that it aerates more easily than glycol based fluids, so it is best to pump the brakes more gently and less aggressively to minimize this being an issue. For this reason, I will typically bleed all of the brakes until I am satisfied and then wait 24 hours to bleed them one more time. This will normally suffice to remove any latent air from the system.

For those looking for additional information regarding the ins and outs of brake fluids, you might want to check out this article on Selecting Brake Fluid. Changing from glycol based fluids to silicone is not for the faint of heart. It is not like changing a water pump, or a starter. However if done with a reasonable amount of care, the results may prove worthwhile.

Good luck... GUSTO

John BX NY

Flush it out the best you can using DOT 5 as I have in my 67 for over 20 years, no need to use alcohol or start all new.

SAE paper 810804 says so. They tested all different ratios of the two fluids mixed with no issues with the seals or anything else.