Rock Auto Parts Disc Calipers

I bought a pair of each caliper set (1965/66 Raybestos RC4047/RC4048 & 1967 Raybestos RC4171/RC4172) for fit checks on early Fairlanes. I wanted to know the difference between the two sets. The 1965-66 set had the hex-head bolts. The 1967 had the 12-point bolts. According to Ford Master Parts Catalogs, the 1965-66 were supposed to have the 12-points, so that was a little confusing to me. Anyway, the quality was adequate for a driver car. They looked good in appearance, but I was surprised to see evidence of past corrosion on the insides of some of the pistons. I am sure this varies with each individual caliper you get, but it is obvious that pistons are reused if they pass inspection. It just did not raise my confidence level about what I couldn't see when what I could see is not top-notch. I would think the pistons would be replaced as a routine. Also, on at least one 1966/67 caliper, there was some rust in the threads where the hose attaches. Nothing serious, but again made me wonder how good interior areas might be. The sealing surface for the brass hose seal also looked rough like casting. Might have come from the factory this way. If you want, and I have your email, and you can handle a 2MB file, I can send you a PDF of the article I wrote. You can just ignore the Fairlane stuff. I can be reached at bobmannel@charter.net.

<BLOCKQUOTE id=quote><font size=1 face="Verdana" id=quote>quote:<hr height=1 noshade id=quote>By the time I purchase new pistons and seals, I'll have more in my old calipers than what they sell the rebuilt ones for.<hr height=1 noshade id=quote></BLOCKQUOTE id=quote></font id=quote><font face="Verdana" size=2 id=quote>

This is the reaction that everyone seems to have when they look at the cost of doing the rebuilding or buying rebuilt. I can't address the specific product you are asking about, but know that most rebuilders don't replace all the pistons. During the rebuilding process someone has to make a judgement call on the castings and the piston condition and this is where the issue of quality can be compromised if they are reusing pistons. The original Ford pistons will last a long time if they are removed from the calipers without damage and aren't corroded. The rebuilder might not have to replace any, or it could be as bad as all four, but with the cost of the pistons I don't see how any of the rebuilders can afford to replace all four. Unless you have complete confidence in the work of the builder how do you trust your brakes without disassembly and inspection to determine if the work was properly done or not?

If you opt to rebuild your own calipers you will at least know what you have. You can bead blast your castings and completely remove any rust in pitted areas and then clean the threads at the line connections. The seal surface of the pistons are easily damaged if mishandled. If you have to replace any of the pistons you should carefully inspect the new ones for scratches or other minor damage that would result in leaks later on. If in doubt return them. I had to send pistons back to NPD three times because of inadequate bulk packaging by the manufacturer. Rust in the threaded areas of the line fittings is common and needs to be inspected and cleaned up with the appropriate taps to ensure a good fit. Stainless caliper lines are a worthwhile investment (unless you are in a concours class that won't allow them). If you look at all these variables and then add the cost of pistons it is difficult to see how a rebuilder can provide a qualtiy product at such low price points. There may be a particular company that is doing a good job and if they could be identified it might be worthwhile. If you do your own you will know exactly what you've got and control the quality. In addition, the calipers were natural finish and most of the rebuilt units are painted black.

If the front calipers need overhaul the proportioing valve probably needs attention too. It would be a shame to push new brake fluid through a corroded proportioning valve to get it to fresh calipers. The body of the valve lends itself to rust over the long term and pitting in the bottom of the cylinder bore is a typical result. There is no mystery to the valve mechanism and it is quite simple. There are companies that will overhaul the entire valve or you can have someone do the sleeving and assemble it yourself. Once the sleeving (stainless) is done it is all about clean, careful reassembly. There is also no better time to replace the caliper hoses and copper sealing washers.

Edited by - round2K on 04/26/2007 05:16:49

My email is bobmannel@charter.net. Email me there and give me your email address. Bob Mannel