Author Topic: 230SL Seized front brake caliper  (Read 4771 times)

dmb777

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230SL Seized front brake caliper
« on: May 21, 2015, 06:54:30 »
I have a 1965 230SL. The front, driver's side caliper is seized jamming the rotor. With brute force (such as driving the car) the wheel will turn. After driving a few hundred meters the brake smokes. (I have only done this once) I acquired the car recently and plan a complete restoration but short run I need to be able to move it inside my garage. So far I have loosened the, rigid, fluid pipe connector at the caliper and loosened the big bolts securing the caliper. About a 1/4 litre of brake fluid leaked from the connector. The brake pads are still in the caliper. The fluid pipe connector appears still to be connected to the caliper even though about 1/2 an inch of thread is showing but continuing to loosen it does not appear to be moving it further from the caliper. With the large bolts completely removed the whole assembly moves in an arc but remains stuck to the rotor. I can see where the pads were last stuck to the rotor, however in removing the road wheel, using a long pry bar, the rotor moved through the caliper and pads. QUESTIONS: !. how do I remove the pads? 2. Is it necessary to disconnect the short, rigid brake fluid tube at both ends? 3. Any suggestions about how to release the caliper? Once I have got the seized unit off the car I will remove the other side and send the pair to the UK for re-manufacture.

stickandrudderman

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Re: 230SL Seized front brake caliper
« Reply #1 on: May 21, 2015, 15:16:46 »
Take the pads out.

Cees Klumper

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Re: 230SL Seized front brake caliper
« Reply #2 on: May 22, 2015, 04:48:28 »
From what I can gather the pads are stuck and can't just be taken out. But perhaps there is a way to drive them out using a punch and hammer from one side of the caliper.

If the fluid leaked out of the connector then trying to take the hose/pipe out further should not make any difference to this problem in my view.
Cees Klumper
1969 Mercedes 280 SL automatic
1968 Ford Mustang 302 V8
1961 Alfa Romeo Giulietta Sprint Coupe 1600
1962 FIAT 1500S OSCA convertible
1972 Lancia Fulvia Coupe 1.3
1983 Porsche 944 2.5
1990 Ford Bronco II

GGR

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Re: 230SL Seized front brake caliper
« Reply #3 on: May 22, 2015, 05:28:44 »
Yes, the rigid pipe needs to come our too. You have two alen bolts at the other end you need to loosen.

If your pistons are not completely stuck, you may have some luck with using a big "pince multiprise" - I don't know the term in English - Clamp it on the ear of the pad on one side (where the pin goes) and behind the caliper body on the other side and apply pressure. Try on both sides. This may push the pistons back enough to allow you remove the pads. Then the caliper will come out easily.

stickandrudderman

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Re: 230SL Seized front brake caliper
« Reply #4 on: May 22, 2015, 10:52:34 »
There is a special tool, a slide hammer, for extracting seized pads but it can still always be done with basic tools and tenacity.

dmb777

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Re: 230SL Seized front brake caliper
« Reply #5 on: May 23, 2015, 17:23:21 »
To all who replied, thank you. I have successfully released the caliper. Your advice was very helpful. After tapping out the pad retaining pins I used an extension bar from a socket  set and a hammer to knock them out of the caliper. I put a strong light on the job (so that I could see to avoid striking the pad material) and struck the metal plate of the outer pad, driving it from the hub side to the outside. Once the first pad was released the second came out easily. As I suspected the rigid fluid tube had aleady released. It was not necessary to detach the the brake pipes. Once off the car the problem became evident. Both sides of the calliper are in poor condition. The rubber seals have a rusty metal ring holding the seals and the associated, thin metal plate is badly corroded. But most important the outside piston is solidly stuck in its bore. The inner piston popped out immediately when I used my compressor to blow air through the fluid duct. From my reading about this matter I expected the car to have Girling callipers but the calipers on this car are ATE. I will remove the offside calliper and send the pair to the UK to be re manufactured. I cannot find a similar service in France, thanks again
DMB.

johndillman

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Re: 230SL Seized front brake caliper
« Reply #6 on: June 19, 2015, 20:37:24 »
By this point, new rubber hoses are seldom a waste of money . . . I'd do them while I was there . . .