Silicone DOT-5 Brake & Clutch Fluid

[vette]

I was just wondering if anyone has used this stuff and how's it work in our Big Healeys? I've only used it once before and that was on a '56 Vette with all original equipment. I used it because the car had just gone thru a rotisery frame off restoration and I didn't want to take a chance on a leak ruinining a fresh, new paint job on the frame or elsewhere. It worked fine on that car. Dave.

 

[Patrick67BJ8]

I was just wondering if anyone has used this stuff and how's it work in our Big Healeys? I've only used it once before and that was on a '56 Vette with all original equipment. I used it because the car had just gone thru a rotisery frame off restoration and I didn't want to take a chance on a leak ruinining a fresh, new paint job on the frame or elsewhere. It worked fine on that car. Dave.

I've used it for years with no problems. Brake Masters, etc., will still wear out.

 

[GregW]

I heard a rumorn a while back that DOT5 was being phased out. Might want to check the lastest on that before making a change.

 

[glemon]

I used it for years with my Healey and other cars, no problems, in fact, I seem to have fewer problems, with my hydraulics since going to DOT 5.

 

[tahoe healey]

If you agitate Dot 5 it holds air bubbles which don't go away and don't resist compression. Dot 3 and 4 absorb water. Chose your poison. In my opinion, both are good but don't mix them. The fear of paint melting with Dot 3 and 4 is nil because it you wouldn't leave it on long if you spilled in on paint. Heat may cause the air bubbles in Dot 5 and that is the reason the military is switching and they are the largest consumer. I had also hear at a tech session that they may discontinue Dot 5. There are isssues with Dot 5 and rubber in the master cylinder, wheel cylinder and hoses. If these are all new rubber I believe you are safe.
There will be others with different opinions.

 

[John Turney]

I've been using DOT 5 for the last 11+ years with no problems. I did a total redo on my brake system before that. I'm glad I didn't have DOT 3 or 4 because I had some initial leaks that would have trashed the paint in the engine compartment. I have one of those vacuum brake bleeders and used it to make sure the air was out of my DOT 5 fluid by applying a vacuum to a container of fluid before pouring it gently into the MC.

 

[Bob McElwee]

I've used it for years in a 67 BJ8 and 62 BT7 with no problems at all.

 

[RAC68]

I initially converted to DOT-5 in 1991 after completing a rebuild of my BJ8P1. My only indication of any difference with the DOT-5 is a sense of a slightly softer peddle. About a year or so ago, I began loosing a little fluid from the system with no obvious point of loss. By the time I was done, I had rebuilt all brake and clutch components and finally identified at the end that the fluid was leaking into the rug padding from the brake master. When rebuilding each component, no corrosion or cylinder deterioration was observed and the units only had to be cleaned before installing new rubber after the same fluid had resided within the systems for about 21 years. Although initially expensive and without any consideration to its additional benefits, in my opinion the DOT-5 has proven less expensive than any other DOT choice and also performed well for someone that does not race his Healey but does drive vigorously.

All the best,
Ray (64BJ8P1)

 

[Patrick67BJ8]

I decided not to implement LEDs after reviewing the reality of the situation. First, LiteZupp LEDs seem to be one of the better examples as many of the less expensive lights only say they deliver adequate light but do not perform with equal measure. Adding to this is the issue of either replacing the flasher with the expense of an electronic unit or adding rather large resistors to each light that will produce heat and waste power. Additionally, although LEDs are expected to provide a longer life than incandescent bulbs, my use of the car will probably allow either to last past my life span.

I initially converted to DOT-5 in 1991 after completing a rebuild of my BJ8P1. My only indication of any difference with the DOT-5 is a sense of a slightly softer peddle. About a year or so ago, I began loosing a little fluid from the system with no obvious point of loss. By the time I was done, I had rebuilt all brake and clutch components and finally identified at the end that the fluid was leaking into the rug padding from the brake master. When rebuilding each component, no corrosion or cylinder deterioration was observed and the units only had to be cleaned before installing new rubber after the same fluid had resided within the systems for about 21 years. Although initially expensive and without any consideration to its additional benefits, in my opinion the DOT-5 has proven less expensive than any other DOT choice and also performed well for someone that does not race his Healey but does drive vigorously.

All the best,
Ray (64BJ8P1)

We have a guy in our club who has a Healey 3000 race car and he uses silicone and says "no problems with it".

 

[johnea]

I have been using DOT 5 for the last 15 years after completely renewing the braking system on my BN6. Never had problems with it. On the tin it says you never need to replace the fluid. I would never go back to using DOT 3 or 4. Topping up or checking the master cylinder reservoir fluid level is less stressful with DOT 5.

 

[John Turney]

.... On the tin it says you never need to replace the fluid. ....

I wouldn't go that far. Never is a long time.

 

[MarshgrassA]

My TR4A has been using Dot 5 since 2000 when resto was completed. I did develop a leak last year that would have messed up my paint but for Dot 5. I don't know if that is a good life span for a MC but I like the idea that a leak won't eat my paint.

 

[moremonkey]

Sorry to revive an old thread, but is the consensus that people don't replace Dot 5 annually like they do with Dot 3 and 4? How long do you all leave Dot 5 in the system before refreshing it?

 

[tahoe healey]

Who replaces Dot 3 and 4 annually?

 

[Bob_Spidell]

Sorry to revive an old thread, but is the consensus that people don't replace Dot 5 annually like they do with Dot 3 and 4? How long do you all leave Dot 5 in the system before refreshing it?

Don't have a regular schedule, but I do a partial replacement every 4-5 years, usually when some other brake or clutch work is required. I've noticed on bleeding the DoT 5 fluid nearest the brakes turns first from purple to clear, then to light brown as it ages, which I attribute to heat. FWIW, I've used DoT 5 (silicone) for over 20 years/100K miles with no problems.

 

[moremonkey]

Who replaces Dot 3 and 4 annually?

Ever since I had a caliper on my daily driver freeze up I've been flushing the fluid annually in all my non DOT 5 cars. It's a whole lot easier to do than rebuilding parts.

 

[BoyRacer]

Denatured alcohol. That's what neutralizes Dot 3 or 4 brake fluid which is what I have always used in my race car. I always have a spray bottle full of denatured alcohol handy to take care of any brake fluid spill, leak or otherwise. In race cars you are always changing, bleeding, repairing, replacing, or rebuilding brake or clutch components and brake fluid is always getting on things. I grab the spray bottle and spray. Even when the fluid gets on the floor. Spray and wipe. It completely eliminates the messy brake fluid problem and the paint is never damaged.

 

[busybrit]

Just to add my input, I only use Castrol LMA in my customers cars with no issues. However, I have used Dot 5 in my TR3 and 100-4 since their initial rebuild using all clean/new components. 17 years in the TR3 and coming up to 12 years in the 100-4. No issues at all. Just make sure you have a new system, cleaning/flushing the old system, well, I wouldn't recommend that as you can't get all the old fluid out. Go with new parts, you should be ok.