Brake pistons - how pitted is too pitted?

[WorldClassAccident]

I have managed to remove 5 of the 6 brake pistons from the front of the Scimi. They all have a ring of rust around them at about the same point. The surface is pitted a bit but I have cleaned the rust off but am wondering if I can reuse them or if they need replacing.

I will try and post some pics if I can get them off the phone

[The 1958 Rocker]

Hi WCA, it all depends on the surface of the piston. As long as the caliper body has cleaned up perfectly, and the rusting to the piston can be removed without leaving any surface damage/pitting then you should be fine. Rest assured we will all agree that if there is any surface pitting to the caliper bodies or pistons, it will cause premature wear or possible leakage to the new seals. In reality, right or wrong, after 37 years in the Motor trade, I have seen tens of kits fitted, and fitted four or five kits myself to cars including a 67 Mustang, and none failed. Ok wise guys, no jokes about flat faces! They all stopped when asked even under very abusive use, so as I said, as long as the surfaces clean up without pitting you should be fine.

Keep going your doing well. I have the fun of stripping and refurbing my suspension, steering and brakes very shortly!

Regards Rocker.

[WorldClassAccident]

3 of the 5 so far have noticeable pitting. 1 of the 6 won't move (yet).

The caliper bodies look fine on both sides so I could just replace the pistons. I will see your your 37 years in the trade and raise you a car 43 years out of the factory that was sat under a tree in a field since '89. ;-)

I guess new pistons wouldn't hurt. I wish I had discovered this before I returned from the autojumble in Bristol as I probably could have picked some up.

[The 1958 Rocker]

If you cannot get that last piston out, one trick we used was to put the other/s back on and wedge them in the fully retracted postion leaving room for the siezed one to pop out. You then connected a grease gun, air fed if you could and pumped 'till it popped out. Bit messy, but better than chissels and grips etc. Not sure it will pop out like "grease lightning" but you never know!!

Rocker

[WorldClassAccident]

It is currently in the vice with the 2 little ones that have come out clamped behind a piece of wood so only the last remaining big one can move. Air compressor ready to blast it. All the others have come out so fairly sure this one will.

It seems to be nothing, nothing, nothing, BANG and it is free.

Trouble is the wife walked into the garage with an open bottle of beer, waved it at me and then walked out to tempt me back into the house. Thus ended the garage session. She is like the Pied Piper that woman!

[The 1958 Rocker]

Hold on, see if you can hold back long enough for her to come back with the beer dressed in her nightie!!

Try for double whammey in one night Ha, Ha.

[WorldClassAccident]

Too late I am afraid. This morning blasting down to Bristol with the roof down and some 'spirited' driving. Looking around the cars and stands at the auto jumble (preferred the car park to most of the stands), blasting back through the rain with the comedy twin tornados in the car with me, achieving something on the car and then my wife smiling and bringing me beer.

You thought you had a good day when your chassis arrived. Mine has been brilliant!