TR2/3/3A Cleaning TR3 Brake Calipers

[Hatman]

Have the brake calipers off my 59 TR3. Pistons and seals are out. The bores are in good shape, so the plan is to rebuild with new seals and SS pistons. What's the best way to clean the calipers? I'd like to ensure the insides are clean, and it would be nice if the outside of the caliper was cleaned up back to an "as new" look as well.

Thanks.


Mark

 

[Don Elliott]

I put the pistons back into the calipers for my 1958 TR3A, covered the open faces with duct tape (Red Green is also a Canadian) and had the bodies sandblasted, then sprayed with acid etch, primer and 2-pack black paint. The painter did all my lower parts and frame with Dupont Imron truck and aircraft paint. 18 years later and they still look like new and clean up in seconds. Others have done them in red - or grey paint to look like cast iron. I never lost points in a concours because they are painted glossy black.

BTW, In 1990 I re-installed those original pistons with new seals for the calipers. The OD of the pistons had a few rusty spots where the plating seemed to have flaked off. That was after 80,000 m iles from new. I filled the system with silicone fluid when I was doing the restoration in 1990 and those pistons have never been an issue during the last 18 summers of driving another 100,000 miles. The silicone fluid in the system acts as a lubricant and I have never had them seize, get tight or develop any more rust.

 

[Hatman]

Thanks Don. How about cleaning the internals? The brakes haven't been serviced in a long time -- like 25 years at least -- and the brake fluid looks more like 50 wt. oil! I'm told mineral spirts, kerosene, etc., can affect the rubber sealing ring in the end plug. Cans of brake clean work okay, but I'd like to be able to soak them in some sort of solvent to make sure the internal passages are clean.


Mark

 

[Don Elliott]

I just wiped the bore dry and then used my air compressor to get any of the remaining sand out. They were clean and dry after this. Then they went for painting. To switch to silicone fluid, I followed the recommendation to change all rubber hoses and seals in the calipers, master cylinders, rear brake cylinders and the clutch hose and seal in the slave cylinder too.

 

[JPeter]

I use Denatured Alcohol to clean all the brake parts. It does not eat the rubber and it dries without leaving any residue. It is compatible with Dot 3 brake fluid if a drop or two is accidentally left in the system.

 

[TR3driver]

What worries me about denatured alcohol is that they generally don't tell you what the denaturing agent is, and it might be something that would adversely affect the seals. For example, one of my cans lists a whole bunch of stuff that "might" be in there, including gasoline!
Here's a MSDS I found just now that specifies gasoline.

So I used methanol instead (available at my local drug store, but I had to explain to the druggist why I wanted it).

However, you can buy purpose-made brake cleaner in any auto parts store.

 

[PeterC]

Thanks Don. How about cleaning the internals? The brakes haven't been serviced in a long time --

I like to use an old frayed throttle cable in my drill and run it through the passages. Cleans them up nicely.

Peter C