Topic: Master cylinder cap black out

[rare70cat]

Eastwood makes a two stage paint called "2K" that is a two stage paint in a "rattle" can. Two stage = durability. $20 a can but BLOWS away regular rattle can crap.

[Building 3]

Al Bundy: Why would you not use DOT 5?

[Al Bundy]

Al Bundy: Why would you not use DOT 5?

For one, the components on a classic were not designed for a silicone based fluid.  And also any contamination through say a vacuum brake booster can be catastrophic to an engine.

[Bob Gaines]

For one, the components on a classic were not designed for a silicone based fluid.  And also any contamination through say a vacuum brake booster can be catastrophic to an engine.

I have not heard of any kind of problem like you describe. I have not heard of any issue with DOT 5 breaking down rubber in seals etc. like you imply. Dot 5 is very commonly used in the classic car community. I have used it for decades on cars of mine and I know others have too. In fact it is particularly recommended for classic cars or vehicles that are garaged for much of their life but must be usable at short notice.Silicone fluid does not absorb water from the surrounding atmosphere while in service and therefore offers greatly extended service life whilst improving corrosion resistance of the main components of the braking system. It is not corrosive like Dot 3 and 4 in case it happens to get on a painted surface. The down side is that it is not for open track cars because it gives a slightly softer pedal feel.You also have to be careful when converting over by thoroughly cleaning /flushing brake lines and rebuilding master, wheel cylinder , proportioning valve etc using the DOT 5 to lubricate the seals instead of Dot 3 or 4 like is normally done. You can go online and read all kinds of info on Dot 5 and short of the downsides issues I mentioned it is very usable in classic cars. I and many others have not had problems . To each their own.

[Al Bundy]

I have not heard of any kind of problem like you describe. I have not heard of any issue with DOT 5 breaking down rubber in seals etc. like you imply. Dot 5 is very commonly used in the classic car community. I have used it for decades on cars of mine and I know others have too. In fact it is particularly recommended for classic cars or vehicles that are garaged for much of their life but must be usable at short notice.Silicone fluid does not absorb water from the surrounding atmosphere while in service and therefore offers greatly extended service life whilst improving corrosion resistance of the main components of the braking system. It is not corrosive like Dot 3 and 4 in case it happens to get on a painted surface. The down side is that it is not for open track cars because it gives a slightly softer pedal feel.You also have to be careful when converting over by thoroughly cleaning /flushing brake lines and rebuilding master, wheel cylinder , proportioning valve etc using the DOT 5 to lubricate the seals instead of Dot 3 or 4 like is normally done. You can go online and read all kinds of info on Dot 5 and short of the downsides issues I mentioned it is very usable in classic cars. I and many others have not had problems . To each their own.

I’m not certain where I implied anything about it’s effect on rubber seals.  And I don’t find the fact that it won’t peel paint is a compelling enough reason to use it.  YMMV

[Bob Gaines]

I’m not certain where I implied anything about it’s effect on rubber seals.  And I don’t find the fact that it won’t peel paint is a compelling enough reason to use it.  YMMV

For one, the components on a classic were not designed for a silicone based fluid.  And also any contamination through say a vacuum brake booster can be catastrophic to an engine.

When you said "For one, the components on a classic were not designed for a silicone based fluid." is when you implied that Dot 5 is not compatible or has a adverse effect on rubber seals. If not what other aspect of the brake system is the silicone based fluid not designed for? The only other thing that is left would be the insides of Terne steel brake lines or the cast insides of the brake calipers or wheel cylinders. Please confirm which item/items the silicone fluid was not designed for if not the rubber seals.

[Al Bundy]

When you said "For one, the components on a classic were not designed for a silicone based fluid." is when you implied that Dot 5 is not compatible or has a adverse effect on rubber seals. If not what other aspect of the brake system is the silicone based fluid not designed for? The only other thing that is left would be the insides of Terne steel brake lines or the cast insides of the brake calipers or wheel cylinders. Please confirm which item/items the silicone fluid was not designed for if not the rubber seals.

Sorry if you got the wrong impression, but you are reading too much into my statement.  DOT 5 didn’t exist when these systems were created, they were designed around what was available.  I’m not challenging the compatibility of DOT 5, obviously it will work though as you mentioned it gives a softer pedal.  That’s something I personally would prefer not to have.  I was asked why I wouldn’t use it and I stated my reasons.  I’m not trying to tell anyone not to use it or that it doesn’t work.

[Bob Gaines]

Sorry if you got the wrong impression, but you are reading too much into my statement.  DOT 5 didn’t exist when these systems were created, they were designed around what was available.  I’m not challenging the compatibility of DOT 5, obviously it will work though as you mentioned it gives a softer pedal.  That’s something I personally would prefer not to have.  I was asked why I wouldn’t use it and I stated my reasons.  I’m not trying to tell anyone not to use it or that it doesn’t work.

I am glad to read that you are not challenging the compatibility of DOT 5. As far as reading too much into your statement we can agree to disagree. I believe you unintentionally misspoke but that is me given the statement. You thought you were clear but you were not. It is no matter now that you have clarified ,thank you very much . At the end of one of my previous posts here I said "to each their own" which I will further clarify in case it was unclear that I feel a personal preference is a prerogative in this case.