Gravity bleeding the brakes

[Faheem]

Can you let me know if it works for you? The main reason I'm tempted to buy one is because of the pressure gauge, having recently replaced quite a few brake lines it should help give me an idea of whether the system can hold pressure correctly or if there are any leaks that need to be addressed. Unlike you I made the mistake of not putting a wedge on the brake pedal and the brake lines have been open for a few months now so mine will only be worse.

 

[Sean d]

Can you let me know if it works for you? The main reason I'm tempted to buy one is because of the pressure gauge, having recently replaced quite a few brake lines it should help give me an idea of whether the system can hold pressure correctly or if there are any leaks that need to be addressed. Unlike you I made the mistake of not putting a wedge on the brake pedal and the brake lines have been open for a few months now so mine will only be worse.

Me too pal

 

[Faheem]

@Sean d mine should be back on the road in the next week or so and once it's ready it'll be straight in for it's MOT. Just hope it goes through after all the work that's gone into it. Truthfully though, I'd rather know if something's wrong before driving it about!! Feels like it's cost an arm and a leg though.

 

[Sean d]

@Sean d mine should be back on the road in the next week or so and once it's ready it'll be straight in for it's MOT. Just hope it goes through after all the work that's gone into it. Truthfully though, I'd rather know if something's wrong before driving it about!! Feels like it's cost an arm and a leg though.

I'm over 3k now pal , when I'm done its going on a mates ramp and he is going to take a look to see if I have missed anything, my concern at the minute is the brakes as I pressure bled them and they are still no good

 

[Faheem]

Wow 3k, I suppose that does includes the cost of a full respray too... Whereas I'll be looking at spending 2-3k alone on just a respray.

Have you tried hooking it up to Inpa, DIS or something similar as there might be ways to bleed the system through there.

View: https://youtu.be/Yw7zPWk4rPI

 

[mrscalex]

I put a load of notes on a recent post. It’s bookmarked on my profile if you take a look there.

In short I found gravity bleeding too slow and difficult. Tony either has the patience of a saint or has a touch that defeats the rest of us. I suspect both

My personal advice is invest in a pressure bleeder. Mine was £50 from Machine Mart and has been one of my top tool purchases.

You’ll need it to do a brake fluid flush anyway. As I believe Tony will confirm fluid condition is now part of the MOT so it’s becoming more important than ever to do.

And the rod to depress the brake pedal while you work is vital too. It works like magic and barely a drop will leave the system while you work on it. Again personally, I would only open up 1 corner of the car at a time. Although bleeding can wait until you are finished.

Bleeding brakes/flushing fluid is incredibly simple once you have learnt a whole raft of little things that will otherwise trip you up. I listed as many as I could remember in my bookmarked notes.

 

[mrscalex]

One more thing. I think it’s what you do with the brake pedal that causes the fundamental confusion.

Working on the brake system = rod to depress pedal to stop fluid leakage

Bleeding the system = leave the pedal alone !!!

 

[motco]

Mike68 has an unresolved issue with brake bleeding. Several other members have tried to help him but he still has a problem I believe. https://zroadster.org/threads/bleedin-brakes.23960/page-3#post-411438 here.

 

[Mike68]

Yep, whatever you do follow the advice to use a rod to depress the brake pedal to stop fluid leaking out if you are working on the brakes. I didn't & have ended up in a whole world of pain. I rebuilt a Stag V8 engine a few years ago & here I am unable to get a bit of air out of the brakes.

 

[motco]

Put a piece of polythene film between the master cylinder reservoir and the cap to prevent air ingress - belt'n'braces!

 

[Z3I]

Ok, here's an update!

I received the pressure bleeder last Wednesday, and couldn't wait to have a go Thursday.

So, all 4 wheels off and everything exposed. Looked at my brake fluid, and because of all the previous gravity bleeding, it is nice and clear.

I connected the pressure bleeder according to the instructions, pumped it up to 1.2bar, and then inspected all my work. Found 1 union at the front with a minute trace of fluid, so tightened further. This is a big plus point of the feeder, revealing leaks, although what I think I found had no consequence.

Released the pressure, and filled the pump with fluid, 2 ltrs, nice and gentle, no new bubbles created, created a small amount of pressure to push the fluid up the pipe as nurses do in hyperdermic needles, then reconnected it to the reservoir. Pumped it up to 1.2 bar again,.

Bled the rear nearside first, then offside rear, then nearside front, then offside front. Used about 1 to 1.5 ltrs, to make sure fluid was all new. This operation with the pump is oh so easy! During the bleed, no new bubbles

Having satisfied myself I've bled the system 100%, released the pressure, and disconnected. Cannot emphasise enough how easy and quick this was.

Next the test. Before starting the pedal was rock solid, more so than before.

The started, immediately the ABS light were out! Then out on the road the brakes were so responsive, pedal harder than before I started.

Back home, garaged the car, and then turned on the ignition to check light out, and all ok all night.

Next morning, tested again, all out1 Before light would have reappeared.

Saturday the same, lights out on starting ignition!

I was away for the weekend, came back today, could not wait, started car, lights still out. Best results yet! Just took it for a run, rakes still 100%, like new, and all lights out.

So I'm considering case solved. I think I had more than one problem, but for sure, the pressure bleeder is a tool I wish I had bought 25 years ago. Can only recommend that you buy one if you have brake and ABS problems, as if it does not cure any problem you have, it tests the systems fully, and gives superb braking.

 

[t-tony]

Easy to use especially when you're on your own.

Tony.

 

[Jack Ratt]

I bought one must be 20yrs ago made by Gunson. You connect it to one of your front tyres to pressurise the system.
Nice useful tool and more or less guarantees that you do the job correctly.
Only problem with an old kit is that manufacturers often redesign the brake and clutch reservoirs and you find that the bits in your kit no longer fit on the car.

 

[t-tony]

Reservoir caps are pretty standard these days. In the past it was mainly far eastern ones which were unusual.

Tony.

 

[buze]

Regarding that pressure bleeder from amazon, just received one -- and I assumed I should be able to build pressure with it empty, just by putting my finger on the tube and pumping...
However air leaks from someplace; this is a 'new' model that has some sort of release valve, and it seems it's leaking from there...

Can anyone confirm it somehow should pressure up empty like that?

EDIT: I used soapy water all over and find out it was the filler cap leaking. I used a small bit of sandpaper to clean the plastic threads on the reservoir and resealed, and now it holds pressure.

 

[buze]

Here's my contraption. This presses moderately firmly on the pedal. Is the the idea?

(That is for changing the calipers, brake lines etc, I'll remove it to bleed the brake!)

 

[t-tony]

That's the idea, you only have to move the pedal down an inch or so from the fully off position to close the ports in the master cylinder.

Tony.

 

[mrscalex]

As long as it fits it will do the job.

I got lucky and my first attempt with a breaker bar pushed against the base of the seat worked well. I think it must be a 24" breaker bar.

 

[t-tony]

If you have electric seats it adjustable !!

Tony.

 

[mrscalex]

If you have electric seats it adjustable !!

Tony.

I didn't even have to move the seat!