Brake fluid damage prevention

[ichthos]

My engine compartment is original and in fairly good shape...except for a small area underneath the battery and the area underneath the brake and clutch master cylinders. Since the damage is contained to these areas alone, I am considering repainting just these areas. What can be done to combat brake fluid damage? Ideally it would be great if there were never any leaks and I was neat in filling the reservoirs, but that is not going to happen. Is there any clear finish that can be applied over the paint to protect it from brake fluid? Any ideas would greatly be appreciated. Thanks,
Kevin

 

[TR3driver]

Well ... you could switch to DOT 5 ...

Sorry, I can't help otherwise. I've heard that DOT 3/4 will even eat "epoxy" paints, although not as quickly as some others.

BTW, I picked up a can of SynPower synthetic brake fluid the other day. The can says "will attack paint finish".

 

[Aldwyn]

Well, at least I dont have to test it on my car now! /bcforum/images/%%GRAEMLIN_URL%%/smile.gif

 

[Tinster]

For what it's worth:

"I did confirm that the silicone fluid did not eat the paint and have read that it does resist moisture collecting in the system but could not confirm the leakage as I felt their seals/cylinders may not be in the best condition and I don't know for sure if they had all of the air out or brake flexing to give them a soft peddle.

I have been a line mechanic in several MG, Triumph and Jaguar dealerships and have had my own shop where I specialized in British cars and have seen how distructive brake fluid can be to paint. I have restored several British cars for my own use but none to "Show Car" class so the long term distruction of the paint around the mastercylinder was never a high priority to me. However, I am presently building a "Show Car Class" car and am considering using silicone fluid.

My final recomendation would be, if you are building a "Show Car", use silicone fluid but if it is just a driver, just be careful with the fluid and use DOT 4 and don't even stand near DOT 3.

 

[RonMacPherson]

Dale,

I thought that you were an architect. Were you once a wrench, or just quoting one?

 

[Brosky]

Ron,

That seems like a quote that Dale is posting from elsewhere, not his words. He may be restoring a car the hard way, but he has never alluded to being a "wrench". Actually, he posts anything but being a wrench.

 

[Guest]

I posted on this very subject about a week ago.

I did a paint test with DOT 3 regular and DOT 4 synthetic fluids. DOT 3 will start to eat paint in less than 3 minutes. Prestone DOT 4 synthetic brake fluid did not harm the same paint sample even after 20 minutes. I still would not let it sit on any painted surface if you can avoid it.

I recently completed a complete brake overhaul and flushed and refilled with Prestone DOT 4 synthetic and I am very satisfied with it.

 

[Guest]

Ron,

That seems like a quote that Dale is posting from elsewhere, not his words. He may be restoring a car the hard way, but he has never alluded to being a "wrench". Actually, he posts anything but being a wrench.

Oh, I thought he said wench!

 

[Guest]

Or wretch.

 

[RonMacPherson]

Dot 4 "Synthetic"? Do you mean Dot 5 synthetic?

 

[NickMorgan]

I rebuilt my braking system on my TR3 15 years ago and used silicone fluid. The car has gone 20,000 miles including several rallies and competitions and the brakes have been perfect. The silicone does tend to spread when it is dripped on the paintwork, but it does it no harm at all.

 

[foxtrapper]

Dot 4 "Synthetic"? Do you mean Dot 5 synthetic?

I'm sure he meant synthetic, as I've seen Prestone Dot 4 synthetic on the shelves myself. Distinctly different than a silicone based fluid. It's supposedly quite a good fluid, especially for the price.

 

[Tinster]

Hey Ron!

You are correct. I am but a simple architect who freely
admits he knows next to nothing about auto mechanic stuff.
My hundreds of stupid questions posted here on the forum
can attest to this fact. I posted:

"I did confirm..............

The quotation mark at the beginning of my post
indicates the voice of someone else is speaking.

I am sorry if there was some confusion. I am
NOT a wrench by any means. But give me a diamond saw
and a slab of good stone and I'll give you a thing
a beauty in return.

So I guess I'm a stone cutter not a wrench. Ha, ha.

regards,

T /bcforum/images/%%GRAEMLIN_URL%%/computer.gif

 

[Aldwyn]

I am using Castrol Dot 3/4 SynTek in my TR6 right now! So there is such a beast.

 

[vettedog72]

Funny how systems seem to "skip" sequence numbers; if you have time to wonder what happeded to #xxx? I don't think I ever saw a can of DOT4 but you just gotta know it was created.

 

[vettedog72]

NOW, I have heard about DOT 4 (from another post) AND DOT 5.1 (from a google)! DOT 5.1 is polyethylene glycol-based not silicone base. I thought DOT was in charge of this stuff; not MOCROSOFT.

Have you seen a can of DOT 5.1 at WalMart, or any of the prolific neuvo part stores? Same thing for DOT4.

 

[RonMacPherson]

My mistake. I noticed the leading quotes, but scanned through too rapidly to pick up on the following quotes.

I just wanted clarification.


Now as for the present(and future) of your skills and capabilites.

You may be an "architect", But you are also becoming a quite capable British Car Owner, which entails mechanical repairs(and in your case component reconstruction).

So you are acquiring mechanical capabilities.

 

[TR3driver]

DOT 5.1 is polyethylene glycol-based not silicone base. I thought DOT was in charge of this stuff; not MOCROSOFT.

DOT 5.1 has the same boiling point performance as DOT 5 (hence the same leading number) but as you say is not silicone based. Just a WAG, but I would guess the DOT was not prepared for the huge backlash and disinformation campaign against DOT 5, so DOT 5.1 is their attempt to smooth the matter over.
<div class="ubbcode-block"><div class="ubbcode-header">Quote:]Have you seen a can of DOT 5.1 at WalMart, or any of the prolific neuvo part stores?[/QUOTE]Not Wally-Mart, but the local discount parts stores used to carry it. They don't anymore. Now they (and WalMart) seem to carry "exceeds DOT 4" "Synthetic" brake fluid instead.

Oddly enough, the can I picked up at Kragen said only "exceeds DOT 4", but also that it's boiling point was 500F, which is DOT 5.1 territory. Makes me wonder if that means it fails some other aspect of DOT 5.1 performance; or the makers just figure that everyone is so confused over the silicone/non-silicone thing that it's better not to mention the point.

Does anyone know of a (new) car that specifies DOT 5.1 brake fluid ?

 

[foxtrapper]

DOT 5.1 has the same boiling point performance as DOT 5 (hence the same leading number)

No, that's not the basis. The DOT numbers are merely sequence numbers, having nothing to do with the boiling point specifications, dry or wet. Just look at the boiling point tables and you'll see what I mean.

According to several of the sources I've read, 5.1 was come up with in an attempt to reduce confusion. That failed, it created more confusion. Quite arguably, it should have been either 4.1 or 6.

Viscosity numbers are where the 5.1 vs exceeds 4 tends to come into play.

 

[TR3driver]

The DOT numbers are merely sequence numbers, having nothing to do with the boiling point specifications, dry or wet. Just look at the boiling point tables and you'll see what I mean.

I must be missing something. Here's the spec I just downloaded from a gov't site :

<span style='font-family: Courier New'>S5.1.1 Equilibrium reflux boiling point (ERBP). When brake fluid is tested according to S6.1, the ERBP shall not be less than the following value for the grade indicated:

(a) DO3: 205 °C (401 °F).
(b) DO4: 230 °C (446 °F).
(c) DO5: 260 °C (500 °F).

S5.1.2 Wet ERBP. When brake fluid is tested according to S6.2, the wet ERBP shall not be less than the following value for the grade indicated:

(a) DO3: 140 °C (284 °F).
(b) DO4: 155 °C (311 °F).
(c) DO5: 180 °C (356 °F).

S5.1.3. Kinematic viscosities. When brake fluid is tested according to S6.3, the kinematic viscosities in square millimeters per second at stated temperatures shall be neither less than 1.5 mm2/s at 100 ºC (212 ºF) nor more than the following maximum value for the grade indicated:

(a) DOT 3: 1,500 mm2/s at minus 40 ºC (minus 40 ºF).
(b) DOT 4: 1,800 mm2/s at minus 40 ºC (minus 40 ºF).
(c) DOT 5: 900 mm2/s at minus 40 ºC (minus 40 ºF).</span>

Later, under labeling requirements it says :

<span style='font-family: Courier New'>If DO5 grade brake fluid, it shall be further distinguished as "DO5 SILICONE BASE" or "DO5.1 NON–SILICONE BASE."</span>

That certainly suggests to me that 5.1 is intended as a sub-category of 5; with the same performance but not silicone-based.

https://www.fmcsa.dot.gov/rules-regulations/administration/fmcsr/fmcsrruletext.asp?section=571.116