Calliper plate lift
Discussion
Ok - fair points chaps - out of interest we usually charge £60/calliper but the one in the picture is in very good condition and would not have been a problem - next time I get a bad one in I will try and photograph it and post it - then you will perhaps understand my concern more.
Loctite is OK because it releases with mild heat and therefore poses no problem removing later. 993 Callipers generally are no problem at all (as they are from newer cars) and it is mainly the old 944 turbos that are a headache - but then they is only warning us of what will inevitably happen to the others eventually - so the point is IMHO well worth making.
Although you can often chisel the allen bolts to turn and unscrew - if you fail or the head breaks off - you are usually left with something that looks nothing like a thread and no way of finding the centre - hence the need for drill jigs.
After 20 years and perhaps one or two previous rebuilds - we have found that the underlying material corrodes even faster than before (despite careful painting with protective paint) and they often then need doing againm after 2 or 3 years. This may be made worse by the tendency to leave the cars parked up while damp from washing compared to more frequent use in the early years.
I posted some months ago a picture of the results of another local garage having tried to drill out the exhaust manifold bolts on a Boxster - and they were a garage!!!!!
Baz
Loctite is OK because it releases with mild heat and therefore poses no problem removing later. 993 Callipers generally are no problem at all (as they are from newer cars) and it is mainly the old 944 turbos that are a headache - but then they is only warning us of what will inevitably happen to the others eventually - so the point is IMHO well worth making.
Although you can often chisel the allen bolts to turn and unscrew - if you fail or the head breaks off - you are usually left with something that looks nothing like a thread and no way of finding the centre - hence the need for drill jigs.
After 20 years and perhaps one or two previous rebuilds - we have found that the underlying material corrodes even faster than before (despite careful painting with protective paint) and they often then need doing againm after 2 or 3 years. This may be made worse by the tendency to leave the cars parked up while damp from washing compared to more frequent use in the early years.
I posted some months ago a picture of the results of another local garage having tried to drill out the exhaust manifold bolts on a Boxster - and they were a garage!!!!!
Baz
I had to do this to a pair of 968 calipers I'm about to put on the back of my 944.
None of the screws would budge at all whatsoever!!!!
In the end I had to cut the plates in half so I could seperate the calipers.
After doing that I drilled a small hole into the centre of each bolt so that I could bash a torx socket into it tightly and then drill a large portion of the bolts head off. Doing this released alot of pressure holding the bolt in place and each one would then undo easily.
Don't drill to far into the bolt, go off centre and you'll knacker the hole's thread possibly.
After that its easy street.
It took me about an hour a caliper inc messing around trying to undo the bolts without seperating the plates.
Thats was in aworkshop with lots and lots of tools!
None of the screws would budge at all whatsoever!!!!
In the end I had to cut the plates in half so I could seperate the calipers.
After doing that I drilled a small hole into the centre of each bolt so that I could bash a torx socket into it tightly and then drill a large portion of the bolts head off. Doing this released alot of pressure holding the bolt in place and each one would then undo easily.
Don't drill to far into the bolt, go off centre and you'll knacker the hole's thread possibly.
After that its easy street.
It took me about an hour a caliper inc messing around trying to undo the bolts without seperating the plates.
Thats was in aworkshop with lots and lots of tools!
Hello chaps
Have just done my 88 944 turbo s calipers. Lots of plate lift/corrosion.
Button head bolts wouldnt shift so I had a mate tig weld another bolt to each one. Then had them shot blasted and powder coated for £30 a caliper, straightened the plates and assembled. New bleed valves and seals while I was at it.
Have just done my 88 944 turbo s calipers. Lots of plate lift/corrosion.
Button head bolts wouldnt shift so I had a mate tig weld another bolt to each one. Then had them shot blasted and powder coated for £30 a caliper, straightened the plates and assembled. New bleed valves and seals while I was at it.
Edited by rich_s on Friday 1st February 21:07
As this is a job I have done myself I may as well chip in.
The button heads on mine had corroded so badly that there was nothing left in the center to get a tool in there to grip.
So I bashed them all out with center punch/chissle.
I used heat on them first to try and breakdown the threadlock(dont melt the dust covers I took mine out ). 2 came out really really easy the rest went to war with me and I do mean war.
they were in there like an alabama tick, They were not rusted in but there was evidence of some kind of corrosion which was probably not helping.
What was left of the screws when I had finished was not much, came close to completely knocking the heads off a few that would have been bad and probably a show stopper.
the caipers themselves showed lots and lots of corrosion I then removed the pistons and sent them away to be powder coated hopefully this will help keep the corrosion away for some years.
as for the plates themselves all but one were ok to use again.
The button heads on mine had corroded so badly that there was nothing left in the center to get a tool in there to grip.
So I bashed them all out with center punch/chissle.
I used heat on them first to try and breakdown the threadlock(dont melt the dust covers I took mine out ). 2 came out really really easy the rest went to war with me and I do mean war.
they were in there like an alabama tick, They were not rusted in but there was evidence of some kind of corrosion which was probably not helping.
What was left of the screws when I had finished was not much, came close to completely knocking the heads off a few that would have been bad and probably a show stopper.
the caipers themselves showed lots and lots of corrosion I then removed the pistons and sent them away to be powder coated hopefully this will help keep the corrosion away for some years.
as for the plates themselves all but one were ok to use again.
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