[6d7gto]

Brass or stainless steel? Who do you recommend?

Thanks.

Robert

[gto4ben]

My preference is stainless steel due to its hardness and resistance to chemicals.

Here's a thread listing some services and photos of results.

[6d7gto]

Originally Posted by gto4ben

My preference is stainless steel due to its hardness and resistance to chemicals.

Here's a thread listing some services and photos of results.

That's the way I was leaning. Whitepost doesn't do stainless sleeves, just brass.

Thanks Ben for your input. Any more opinions?

[Stuart]

While brass is softer, if the fluid is changed periodically so it doesn't get contaminated with dirt I suspect it's still going to take next to forever before it wears out. It will also be more resistant to corrosion (particularly if they use 400 series stainless - if you go that way, find out what grade stainless will be used.)

[mgarblik]

I had 4 calipers and the master cylinder sleeved with brass from White Post Restorations over 30 years ago. It was for an early De Tomaso Pantera I did a mechanical restoration on. The car used weird Italian components that were only on the first couple hundred cars, then the supplier went out of business. So had little choice. The car was just sold in the last year and never had any leaks or issues in all that time. The fluid was changed a couple times. So brass would not scare me.

[6d7gto]

Originally Posted by Stuart

While brass is softer, if the fluid is changed periodically so it doesn't get contaminated with dirt I suspect it's still going to take next to forever before it wears out. It will also be more resistant to corrosion (particularly if they use 400 series stainless - if you go that way, find out what grade stainless will be used.)

Karps uses "304 drawn stainless" (whatever that is). Apparently, Karps does not use brass while White Post does not use stainless...so if I go with either one of these companies, I really have no choice.

Stuart, is there any drawback to stainless?

[694.1]

Stainless is harder to work, I have heard it said that brass conforms easier to the bore and can help prevent leaks..
Maybe a horse apiece?

[694.1]

Please delete.

[Stuart]

304 stainless is pretty corrosion resistant, my concern was if they used 400 series stainless which can rust. I suspect using stainless is more expensive than brass, but that's about all I can think of. I'm not a metallurgist, but both my brothers are - I'll shoot them an email to get an opinion.

Edited to add a quote from my brother the expert.

The only technical point I can think of regards salt. Type 304 SS will pit in a saline environment, so I suppose much depends on the seal or boot configuration to exclude the environment. I also don't think that any 300-series stainless steel would hone very well. There is a galvanic series difference between either brass or stainless and cast iron but that doesn't favor one over the other. Again, it relates to exclusion of salt water.

Based on what he said I think I'd prefer brass. A collector car won't see much salt, but at least where I live there's still going to be some residue left on the streets in the spring. If you live near an ocean it's also a concern. His point about honing the cylinder should be considered too.

Edit X2: Gray iron, 304 stainless, and yellow brass all have different coefficients of expansion.

Gray iron 6.7 micro inches per degree F
304 stainless 9.6 micro inches per degree F
Yellow brass 11.1 micro inches per degree F
(one micro inch = 0.000001 inches)

This means the sleeves will expand more than the brake cylinder body as they heat up, although I don't know if it's enough to make any difference either way - even if the brake temperature gets to 400 degrees, the difference between iron and brass is still only about 0.001".

[6d7gto]

Originally Posted by Stuart

304 stainless is pretty corrosion resistant, my concern was if they used 400 series stainless which can rust. I suspect using stainless is more expensive than brass, but that's about all I can think of. I'm not a metallurgist, but both my brothers are - I'll shoot them an email to get an opinion.

Edited to add a quote from my brother the expert.

The only technical point I can think of regards salt. Type 304 SS will pit in a saline environment, so I suppose much depends on the seal or boot configuration to exclude the environment. I also don't think that any 300-series stainless steel would hone very well. There is a galvanic series difference between either brass or stainless and cast iron but that doesn't favor one over the other. Again, it relates to exclusion of salt water.

Based on what he said I think I'd prefer brass. A collector car won't see much salt, but at least where I live there's still going to be some residue left on the streets in the spring. If you live near an ocean it's also a concern. His point about honing the cylinder should be considered too.

Edit X2: Gray iron, 304 stainless, and yellow brass all have different coefficients of expansion.

Gray iron 6.7 micro inches per degree F
304 stainless 9.6 micro inches per degree F
Yellow brass 11.1 micro inches per degree F
(one micro inch = 0.000001 inches)

This means the sleeves will expand more than the brake cylinder body as they heat up, although I don't know if it's enough to make any difference either way - even if the brake temperature gets to 400 degrees, the difference between iron and brass is still only about 0.001".

Great wealth of information! Nice to have such a close relative with expertise who is willing to share their knowledge. Please thank him for me. And thank you too!

[6d7gto]

Originally Posted by mgarblik

I had 4 calipers and the master cylinder sleeved with brass from White Post Restorations over 30 years ago. It was for an early De Tomaso Pantera I did a mechanical restoration on. The car used weird Italian components that were only on the first couple hundred cars, then the supplier went out of business. So had little choice. The car was just sold in the last year and never had any leaks or issues in all that time. The fluid was changed a couple times. So brass would not scare me.

Thanks for your input. Brass doesn't scare me either. Especially here in Southern California. Probably more salt in the air than moisture! I will be changing fluid too. Just gotta choose which brake company to use. It's down to Whitepost or Karps.

Thanks to everyone who responded.