Non-75/ZT brake question

[mantianak]

I've had to replace the master brake cylinder on my wife's car which went quite well but I've now come to bleed the brakes. The front drivers side brake isn't letting any fluid out, the passenger side flowed out like it should do. I bled the rear ones before realising the cylinder was knackered so I know they bleed ok, so it's just the front drivers side. Is there likely to be a blockage somewhere or something else? Car by the way is a Rover 100.

[T-Cut]

Do you mean with the caliper bleed nipple fully loosened, you can't force fluid out using the brake pedal?

TC

[mantianak]

That's correct. Forgot to mention I also used an eze-bleed kit, the one that plugs up to a tyre. Both methods didn't work. I did think about increasing the tyre pressure but thought it was a bad idea. Other than taking the pipes apart I'm stuck for ideas as I'm not familiar with the car yet.

[mantianak]

I just had the caliper off and diconnected the brake pipe going into it. Fluid poured effortlessly from the pipe so the problem is with the caliper. Unscrewing the bleed nipple and looking into the hole I could see it's pretty blocked up on the inside. Can calipers be cleaned from the inside or is it a new caliper job?

[Lates]

You could pump out the piston and clean up any nasty bits. If the nipple is removed does the fluid flow ?

[mantianak]

Removed the nipple, no flow. Looks like there is dirt not in the nipple but the caliper side.

I should try cleaning it as you said. How would I remove the piston? Just pump the brake while still on the brake line?

[Lates]

Originally Posted by mantianak

Removed the nipple, no flow. Looks like there is dirt not in the nipple but the caliper side.

I should try cleaning it as you said. How would I remove the piston? Just pump the brake while still on the brake line?

I would but you need two people once the piston has popped you need to clamp off the flexy

[mantianak]

Cheers lates. Will give it a go. The flexi isn't likely to sustain damage from clamping is it?

[BigRuss]

Originally Posted by mantianak

Cheers lates. Will give it a go. The flexi isn't likely to sustain damage from clamping is it?

Depends how you clamp it, if you have a brake hose clamp you should be fine

[mantianak]

Just finished the job For all those interested here's what I did......

1) disconnected the calliper and removed brake pads and one side bolt (the ones holding the calipers together).

2) Tried as lates said with the brake pedal but too much air in the system from changing the master cylinder, it wouldn't pop the piston out. So decided to remove the calliper completely.

3) clamped the fexi brake hose with mole grips, nicely fine tuned clamping. Then removed the brake hose then the calliper.

4) As the hole for bleeding was bunged up I unscrewed the brake nipple and screwed it into the inlet hole (where the brake pipe goes), left the nipple slightly open and got out the foot pump! A few pumps and the piston shot out.

5) Cleaning! And wow did it need a clean! Trying the foot pump method didn't work on the bunged up bleed hole. That shows you how bunged up it was that it moved the piston more than 2mm or dirt. So instead used a pin to poke out the dirt then used brake fluid & a rag to clean the inside.

6) all back together again.

Went for a test drive. Brakes feel a lot better and actually stops the car now! Although it feels a bit spongy still, strange though as I used almost 3 litres of fluid. Is there likely to be a small airlock somewhere? How to shift if there is?

It's been a big day of learning for me (glad I took the day off work to do it). Has shown me how important it is to make sure brakes are regularly cleaned. I'm quite interested to see how the other cylinders are on the car and also on my ZT!