Brake Bleeding Problems

[DanSE4]

Afternoon/Evening all!

Putting this here for some decent opinions as I really can't be bothered to have to sift though all the Facebook rubbish from people who have no idea what they're talking about.

So, scenario first.

Calibra emerged from my garage yesterday after it's 6 month (not quite, went away at the end of September last year) hibernation so wanted to get a few things done prior to MOT & then tax for the beginning of April.

First off I did the rear disks & pads...



Then I replaced the front Flexi's with Goodridge braided ones.



They went on fine & the fronts bled ok.

Noticed that the rears needed a little more attention so left those for today. Fitted those today after discovering I needed an in-line join as once I'd dismantled what I had, I was left with two female ends.







The rear offside was off for about an hour while I went out & got the in-line joins so lost a fair bit of fluid out of that, the nearside rear lost quite a bit less as I did that afterwards once I had the bits.

Once everything was on I started the bleed with the nearside rear (being the furthest from the master cylinder) & a few bubbles, a little "foam" later got good fluid through & that was done. The rear offside does not want to play. I think I owe Gail a leg massage tonight as we just could not get anything through on that side!

It was blowing a few bubbles, a little fluid came through but then it just stopped & must've spent 10 mins or more swapping places & pumping that pedal! There just seems to be nothing coming through now, the odd little air bubble but nothing more & the fluid level in the reservoir isn't dropping to suggest anything is being pushed through.

I'm sure the flexi's are fitted fine (I'm no stranger to brakes & have fitted replacement brake lines & bled them more times than I care to remember), I got a little fluid through it when I fitted it to the end of the metal pipes under the car & then only joined that to the next metal pipe to the caliper & at first the bleeding seemed to be pushing air bubbles through. It seems to have stopped now & nothing is coming through & the fluid level in the reservoir isn't dropping. Tried the other 3 corners again & they all bled fine & were pushing fluid through.

Had the bleed nipple off the rear offiside caliper, can blow through it & refitted it with a little copper grease.

Part way into the bleeding my brake pedal suddenly took on a "click" where it felt to be catching halfway down it's travel & then again halfway back up it. There's also a "hiss" from it which can be heard both in the car & from the master cylinder when it's at the very bottom of it's travel.

Any ideas welcome cos I've packed it all away again until next weekend & will cancel the MOT I had booked for Tuesday!

[v6 steve]

so in summary fluid isnt coming out the bleed nipple ? does the wheel lock up when pressed ?

[DanSE4]

so in summary fluid isnt coming out the bleed nipple ? does the wheel lock up when pressed ?

In a nutshell, the other 3 corners bleed fine but nothing seems to be coming through this one.

Took the bleed nipple out of the caliper & still nothing. It did at first, the bubbles were coming through the plastic tube from the nipple with each press of the brake pedal & then it all just stopped.

The brakes are currently useless until the pedal hits the floor & you get a little "bite" but that's it.

[v6 steve]

silly question but is there a leak any where else ? swap nipples over see if it will bleed the other calipers

[Allys Cally]

disconnect the pipe from the caliper and see if any fluid comes out the pipe when you press the brake if it does there must be a block in the caliper itself.

[DanSE4]

Car's away now until next weekend so can't start playing around with stuff again until then.

Took bleed nipple off, it blew through fine & went back on with a little copper grease to make sure it's not leaking from the thread.

I was definitely getting fluid from the metal pipe, through the new flexi & to the metal pipe to the caliper so I don't think there's a block somewhere (the bleed nipple was coughing air & bubbles initially).

I'll pinch Daddy-In-Laws electric bleed kit for next weekend & see how that fares, still not sure about the way the brake pedal was behaving today though?

[rips]

Not an answer to your problem, but a tip from somewhere else:

If you want to stop fluid draining while the brakes are disconnected, remove the reservoir cap. put some cling film over the top then put the cap back on. This should seal it...a little like putting your finger on the top of a hose full of water.

[GreyDJ]

As I understand it

1. all nipples tight, pedal to the floor, no resistance apart from bit at end of travel
2. undo any of the 3 nipples on the OK corners, pedal to the floor, some fluid out and clear
3. undo last nipple, pedal to the floor but nothing out.

From my experience you could have so much air in that pipe, back to the ABS unit, that pedal pumping, one stroke at a time, won't clear it because closing the nipple on the up pedal stroke has no effect due to all that air. Excellent plan to put an electric pump onto it as continuous pressure in the fluid system is probably the only way to vent it once you are at this point. Open to air gravity feed might have worked but not once there is an air lock in the up pipe out of the ABS unit which it looks as if you probably have, especially given your comment about the loss of fluid from that pipe when you went to get the new part.

If this clears the system but pedal pressure is still not there, a possibility is that all this pedal activity has flipped the seals in the master cylinder. Hopefully it won't come to that.

As to rips suggestion, that works if air can't work its way back up the pipe displacing the fluid. So try to make sure there is a low point near but not at the remote open pipe end.

John

[DanSE4]

As I understand it

1. all nipples tight, pedal to the floor, no resistance apart from bit at end of travel
2. undo any of the 3 nipples on the OK corners, pedal to the floor, some fluid out and clear
3. undo last nipple, pedal to the floor but nothing out.

Yup, that's pretty much it.

The one that I can't seem to get any fluid through is the O/S/R & that one was left open for a lot longer than the rest as I was out getting parts, a fair puddle on the driveway!

Hopefully it is just a case of there being so much air in that pipe now that the brake pedal is ineffective at pushing the fluid through. I've always borrowed the electric kit before for bleeding / brake fluid replacing so this is the first time I've tried it using just the pedal. Sod doing that again!

[Callyman]

Push the fluid through, swear by these, then use traditional method once pipes all full.

http://www.halfords.com/workshop-tools/ ... -eezibleed

[DanSE4]

The piece of kit Andy (Daddy-In-Law) has is great.

Fill it's own reservoir up with brake fluid & it has a pipe from it with a choice of caps to suit the reservoir on your car. Fit that pipe with the appropriate cap to the car, attach the crocodile clips from it to your battery, close the valve on it & turn it on.

It starts pressuring the system & pushing fluid in, once it reaches pressure it turns off. Then go to the required corner & loosen the bleed nipple, as soon as the pressure drops from that it turns back on again & starts pushing the fluid through & filling from it's own reservoir. As soon as the bubbles have stopped & there's clean fluid coming through, close the nipple & it turns itself off when it detects the pressure is back.

When it's all done you just release the valve on it, remove & top up your brake fluid reservoir if required.

I've never seen another one like it & I'm always checking eBay etc to try & find one.

I'll get a pic of it this weekend.

[Callyman]

That kit does the same but air pressure pushes it.

[DanSE4]

I've never used the ones that run off tyre pressure, are they any good?

[GreyDJ]

Yes, they work, I've had one for years.

It operates as you describe the electric one except that it has a pipe to a front tyre valve rather than its own pump. Doesn't take much air either.

I don't use it with fluid in its reservoir, I found that a bit messy, especially if it tipped over. I just use it with an empty bottle to pressurise the M/C and keep an eye on its reservoir. I recommend it (think there is only one made).

[rips]

They do the job similar to Andy's kit. Not much air is displaced so you won't have to keep stopping to top up the tyre.
I have one if you want to try it out.