Need 10 ton hydraulic pump to force brake caliper pistons out.....

[HuskyMan]

I'm thinking of buying one of these 10 ton hydraulic pumps then connecting to a brake hose connected to brake calipers to force stuck pistons out of the bore..

Which one of these two do you think would do a better job for this application?

https://www.amazon.com/Strongway-Hydraulic-Pump-Gauge-Hose/dp/B00ULDGP2S/ref=sr_1_2?ie=UTF8&qid=1528386032&sr=8-2&keywords=strongway+10+ton+hydraulic

or...

https://www.amazon.com/Hydraulic-Hand-Pump-Pressure-psi-43/dp/B00XKD069O/ref=cm_wl_huc_item#feature-bullets-btf

[HuskyMan]

I have a medium sized air compressor that goes to around 120 PSI. I wonder if I could connect a brake hose and use it to force the brake pistons out of their bores?

[HuskyMan]

Or what about this idea? Would a motorcycle brake master cylinder provide enough force to move pistons out on mercedes calipers?


https://www.youtube.com/watch?v=rHvIA_--BAs

[Diseasel300]

Uh.....why? If the calipers aren't seized up you should be able to pop the pistons out with the brake pedal or with compressed air. They should come right out without having to reinvent the wheel.

If your pistons are that stuck, use the calipers as cores and get rebuilt ones. You'll be money, time, and frustration WAY ahead.

[tangofox007]

Originally Posted by HuskyMan

I have a medium sized air compressor that goes to around 120 PSI. I wonder if I could connect a brake hose and use it to force the brake pistons out of their bores?

I have removed hundreds of caliper pistons with compressed air. Be careful, though. You can hurt yourself. You wouldn't want to have survived the garage door experience only to wind up in the ER with some broken fingers because of a brake caliper.

[Father Of Giants]

It shouldn't take a that much force. Once they do come out, go ahead and post pictures of the bore and piston, worst comes to worst it might not be rebuidable.

I've used Phosphoric acid and copper wire brush to gently remove corrosion. Works very well.


If you're going to do that you'll need some badass lines to take the brunt or they'll burst.

[vonsmog]

I have used a grease gun to remove the pistons if stuck. Makes a mess but they come right out.

[MCallahan]

I'm with Diseasel300, if they are that stuck, they are probably junk. Could rebuild them, but if they are pitted, they are going to seep.

[optimusprime]

And like above if piston is stuck in the bore of caliper it will be rusty inside and a waste of time and effort to repair and re seal them. You could remove caliper and line the caliper piston with emery paper and then use an internal expandable puller .It might come out ,but any surface damage is not acceptable ;.

[Junkman]

Put a rag around one piston and blow it out with air. That will protect your fingers. Reinsert, hold with a clamp and blow the other out. Any caliper stuck so bad that air doesn't work needs more than can be done easily and can be sent to the remanufacturer.

[barry12345]

The source has a hook up kit to use their injector pop tester for this. The kit is just a steel line with the right fittings to hook a brake line to. Injectors should be checked anyways.

Or 100.00 lands a diesel pop tester off ebay at your doorstep. You then just make an adapter up to hook it to brake lines. The adapter could just be a used line and hose fitting from a wreck. With you getting a fitting that fits the pop tester brazed on to the other end. Even new short brake lines are dirt cheap to use instead. To make up your adapter.

You always would bleed the caliper when using hydraulic force. . Before applying the real pressure. Otherwise the compressed air ahead of any fluid could result in a really serious pop out of the caliper piston. Even jamming it against any stop bar you might be using during extraction.

Mercedes dealer maintenance program for these cars. Required a check of the injectors spray pattern etc. Every 100k. There may still be a few sets of injectors in operation that are well over. I suspect I have a few of them on hand myself.

[Dubyagee]

Couldnt you connect it back to the car and pump the brakes while it was over a bucket. The fluid needs to be flushed anyways.

[barry12345]

Originally Posted by Dubyagee

Couldnt you connect it back to the car and pump the brakes while it was over a bucket. The fluid needs to be flushed anyways.

You could do this of course. In general on these old master cylinders. Bleeding or their use for anything unusual should be tempered. It may ruin the master cylinder. You never know once pushing the piston seals over the unused portion of the very old bore is going to do to the seals.


I only pressure or vacuum bleed these brake systems. The easier you can make it. The more likely you are to do periodic brake fluid changes as well.


Remember type 4 brake fluid resists water absorption somewhat better. Also remember to remove as much old fluid as practical with a turkey baster or whatever from the master cylinder. Before adding new fluid. You may save on the amount of new brake fluid required.


Also for what it is worth. As far as I know. I may be the only guy that does this. I take a snug fitting piece of fuel hose. Put some high temperature grease on the brake bleeders. Slide the hose on and cap it with a dab more grease.


I live in an area where bleeder screws can really become hard to deal with. Plus some are actually rusted so bad they are structurally weak. They will just break off at lower torque than is required to loosen them. Essentially the are just a hollow tube remember. .So they rust internally as well as externally.


So common here. You take a torch and heat the bleeder screw area till it is red. Quench the area with water. Repeat this two more times. The bleeder screw will then back off. Strong heat sources are a very required tool when you live in rustbelt areas.

[vstech]

I second the grease gun tip... put a zerk fitting into the bleed screw hole... voila! Out pops the piston....

Clean it out well!