Hello,

I've just completed rebuilding the front ATE/Teves calipers on the 76 300D, or at least I hope so.

Some concerns:

1. Getting the heat shield down far enough. The book says to get the edge of the heat shield at least .1mm below the surface of the elevation on the piston. I've managed to "beat" the thing down to about flush (more like pressing with the old pads/ washers and a socket and clamp, etc.) What is the reasoning behind this, is it a squeal issue? Without the special tool, I'm about to give up and put it on the car unless anyone has a really good idea.

2. I used "Raybestos Hydraulic Brake Cylinder Assembly Fluid" sparingly to lube the parts for assembly. Suppose I should'a just used brake fluid.

3. There were some rust spots and surface imperfections in the bore. Not totally rusted out or anything, even the book says minor imperfections can be cleaned. (I used 1, and 00 steel wool). I didn't really have a problem with leaks or sticking before so I hope I can just put them back in service.


DOT 3 or 4 in this car? I bought the ATE DOT4 off fastlane, but the brake res cap says use DOT 3.

Thanks in advance for the help. Minor issues I'm sure, but any feedback is appreciated.

__________________
63 220S W111
76 300D W115
2013 VW JSW TDI M6

previously-
73 280 SEL 4.5
86 300E 5 speed
2010 VW Jetta TDI M6

1. When I did the Bendix calipers, I had the exact same problem. I could not get the heat shield below the piston, no matter how much I tried. Without the special tool, it seems hopeless. I installed them and they appeared to have no issues running flush.

2. Cannot comment on the Raybestos fluid. No knowledge of what it is.

3. If you have cleaned up the bore carefully with steel wool, and there are no raised areas, you will be fine. Pay particular care to the area outside the seal. This area can get a bit corroded and cause the steel to be raised a bit. This will cause the piston to contact this raised area during the installation of the piston and it will give you fits. I had to carefully file this area using a fine file to get the rust removed.
However, if the piston has any rust anywhere on the outside surface that contacts the seal, you must replace it.

DOT 4 is the best fluid you can buy now. At the time of manufacture of the vehicle, DOT 3 was the only thing available AFAIK.

Okay, thanks Brian. I think I'm going to go with it. The piston wasn't 100% perfect, but the blemishes there were very, very minor. The pistons went in easily. I had to start over on one caliper after a visit to my mechanic for some tips, went in much better after the second cleaning.

__________________
63 220S W111
76 300D W115
2013 VW JSW TDI M6

previously-
73 280 SEL 4.5
86 300E 5 speed
2010 VW Jetta TDI M6

The heat shields will be fine, they only contact the rear of the backing plate anyway. You don't want any part of the shield to get between the pad and the piston, otherwise it won't matter.

Ideally they would not touch the backing plate, but they will work fine no matter what.

I use fine sandpaper to remove the corrosion in the caliper bore above the seal, there is usually a ton of crud there from embedded dirt when the calipers get overheated, and the piston is both very difficult to get back in AND sticks if this is not removed. Piston should go in with light pressure (I can get the rears on the W124 in with finger power, for instance, but they are tiny).

You must be VERY carefull to remove ANY traces of abrasive if you do this -- otherwise, the caliper will inevitabley seize.

If the pistons "spring back" a bit when pushed down firmly, you are fine.

The brake lube is exactly what you want to use, it doesn't run off during assembly like brake fluid does and makes the job easier.

Peter

__________________
1972 220D ?? miles
1988 300E 200,012
1987 300D Turbo killed 9/25/07, 275,000 miles
1985 Volvo 740 GLE Turobodiesel 218,000
1972 280 SE 4.5 165, 000 - It runs!

Coolness. I'm hoping it will hang out and prevent corrosion too.

I blew everything off with an air compressor several times and sprayed it all down with brake cleaner before assembly. The pistons all went in with finger pressure.

Thanks for all the help. With any luck, the calipers, rear sub mounts and diff mount will be on today and a real test drive might take place.

__________________
63 220S W111
76 300D W115
2013 VW JSW TDI M6

previously-
73 280 SEL 4.5
86 300E 5 speed
2010 VW Jetta TDI M6