The major problem with the spring plates on the calipers is not really corrosion but brake dust buildup. You have to make an effort once a year or so to clean out behind them (I also learned the hard way) or eventually the plates will permanently deform. The usual "porsche mechanic" solution is to file the edges of the pads but that only delays the inevitable. Now whenever I bleed the brakes I also clean between the spring plates and the caliper.

 

Sound advice.

Thanks.

 

I'll second that, but add the caveat that here in the UK if you use your car in the winter, expect some corrosion behind the caliper plates, my fronts were absolutely horrendous, I don't reckon they'd ever been looked at.
I remove corrosion about 1/2mm deep in places, possible more........plus the brake dust build up which occured around the plate bolt holes, this had definitely squeezed the brake pads, to such an extent the MOT examiner made the statement about one side being more efficient than the other, I knew exactly what he meant when I stripped them down.

kevin.

Sorry no photos, can't take cameras to work.......

 

The problem is because the calipers are aluminium not cast iron, to save unsprung weight for that fab Porsche handling, but the steel plates are needed to stop the pads wearing grooves in the caliper body.

But corrosion always happens between aluminium and steel (ask landrover), so the plates ideally need doing every few years if the car is driven year round. They improved it after 993, don't know how. The accepted method of removing the bolts is to heat with a gas torch - if they're done reasonably often they shouldn't be too hard to extract each time.

So, the problem is a side effect of your Porsche's avant garde technology from 1989! BTW I've often heard too that Porsches are mechanically a delight to work on compared to other cars..

As mentioned above, if you can't face the caliper plate job, as long as its not heinously bad, you can grind the sides of the pads with an angle grinder in about 20 seconds, and hey presto, in they pop - sounds like a bodge, but I learned it from Ring Racing! As long as the pads are moving, so what if the sliders are sitting out a little?

 

Ahhhh All becomes clear The need for those plates was baffling me. I have never had this problem (hence the rant) of pads that don't fit. Im a fan of less un sprung weight( ok I know I have 18 inch wheels)

I take it all back . Pehaps the title of my thread should have been "why is nothing straight forward" instead of easy.
I was also a little frustrated as I was under time pressure. I needed the car back on the road so I could go pick the kids up And expected a simple job.

Now I know what the crack is, I can either be prepared with new plates or as the button head screws seemed to be very corroded I can ask John to do it.
I think I have read about these plates before but sometimes I need to see for myself to get my head around it. Guess its hard for me to learn new tricks at my advanced age

As usual rennlist provided the answer. Thanks

 

I used the trick of a small engineering chisel to drive my screws out, replaced the screws with SS buttonheads.