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SRT8 Sheared Front Caliper Bleed Screw

5.3K views 9 replies 6 participants last post by  devilmaycare  
#1 ·
Hi All,

Thought I would post the following experience whilst replacing seized inner pistons on the front Brembo calipers.

I used the stainless piston kit from our friendly guys at Custom 300C Shop (thanks guys). I also upgraded the Discs (Rotors for you folks over the pond) with the EBC Ultimax Blackdash USR Slotted brake rotors and Yellow Stuff Pads (I've had the kit for 9 months or so and fool me, waited until MOT in Feb to fit them in the cold and wet).

Anyways, Piston replacement went well but slow. There's plenty of write up's on the forum so I won't bore you other than it's quite tough to get the old pistons out. I recommend you trust yourself that you have fitted the first piston ok. When i pushed the first piston in it was really difficult then it just suddenly gave and dropped to the base of the bore all of a sudden. I just didn't think this was correct so struggled like blimey to get it out again to find nothing wrong, seal seated ok. Having swapped all 8 pistons, I fitted the discs, refitted the calipers and thought I was on the home run. How wrong was I.

Upon attempting to bleed the front calipers one of the bleed screws I found was tight as hell (even though I had sprayed it with plus gas over a few days). Whilst trying to free it the bloody thing sheared off. Well I was left with a non runner and I feared a large bill for a new caliper.

I attempted the usual drill down the center of the screw and use an easyout but it just wouldn't budge. In the end the top of the bleed screw just started to disintegrate so that was a non-starter.

I had one last trick. I built up the center of the bleed screw using my MIG welder and attempted to weld a nut on the top. This took three attempts but I eventually got a nut to stay on with sufficient weld to hold whilst undoing the bleed screw. Success. I finally got the screw out. See the photo's attached.::biggrin::

The new bleed screws are available through Fiat but they are expensive. I bought two front (separate items) and 1 kit for the rear just in case (covers 1 caliper because they have two bleed screws in the rear). This came to ÂŁ35.00.::frown:: I've given the details to Tim at the Custom 300C Shop so he is looking at the possibility of sourcing some a bit cheeper.

All the bleed screws turned out to be really difficult to loosen and required a bit of heat. I subsequently used some copper grease on the threads when tightening them back up.

Hopefully this will help someone else out there if they end up in the same fix as me.

PS. MOT coming up this Sunday. I'll let you all know if it's success or hell.

Cheers,

Craig.
 

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#2 ·
I've not had to do my calipers on the 300c yet but I did have the same problem on my old PT Cruiser a couple of years back when I did all the calipers on that. At that time I was reminded of the old trick of dropping a decent fitting ring spanner over the bleed screw and tapping it backwards and forwards repeatedly with a small hammer until the screw is loose. Unfortunately I had already broken one bleed screw before that but it worked absolutely perfectly for all the others!
 
#4 ·
Not necessarily.... I changed my fluid on my 06 for the first time in 07 (went to a better grade brake fluid), mine were seized on the fronts and still looked new. Calipers get extremely hot, those two metals heat and cool at different rates and also have the pleasure of brake dust getting everywhere... stuck happens.

Now I completely agree with changing the fluid regularly though, one of the most overlooked things out there is the fluid that stops your car... crazy! I also agree that taking any screw in and out regularly should keep it 'free' so to speak... just don't be alarmed if one time it's not! Great point Andrew!
 
#7 · (Edited)
Changing fluid per year seems overkill, modern brake fluid doesn't absorb water like the old stuff.

Over zealous garage mechanics are the problem, they overtighten the bastard bleed screw.

Finger tight, then an eighth of a turn. It only needs to be nipped to be sealed.


Remember, most important, put the rubber thing
over the nipple when you've pumped out all your fluid [ Oooerrrr, Missus ]
 
#8 · (Edited)
Changing it every year is a little overkill for sure, but every 2 years is best for a car that's driven daily, lives outside, and is exposed to all kinds of weather and driving conditions. Even modern glycol based brake fluids (DOT 3, DOT 4, and DOT 5.1) still whick the moisture out of the air. That is why brake fluids have both a dry and a wet boiling point. Dry is when the fluid is new and there is no moisture present in the system. Wet is when the system is contaminated with roughly 3% moisture by volume of fluid in the system. Doesn't take very long for your fluid to reach it's wet boiling temperature, which is significantly lower than the dry temp.