Bleeding brakes

I recently changed my brake fluid as it was desperately required, and since I've had a very long pedal travel before anything much happens. There is a load of takeup with minimal braking force throughout and then the pedal firms up and is fine, so it's not a major airlock, but it certainly is unpleasant to drive.

I've read this:

http://www.mkivsupra.net/vbb/showthread.php?255279-brake-issue-problem-diagnosis

And I've had a look at the PDF Chris attached to that thread. I think my bleeding technique isn't doing the business, even though it's worked fine on a few other cars in the past (my Mondeo currently has an ace brake pedal feel, which is really annoying me as I want the Supra to be like that). I even did the Supra about 6 to 8 years ago and that has been fine since (the old swamp water fluid came out a burgundy colour, it wasn't happy )

Anyway. I read in the PDF that person 1 should pump the brake pedal several times and then hold it down, and only then does person 2 open the bleed valve and then shut it again. Sounds interesting. I'd just been opening it, getting person 1 to push the pedal to the floor, and closing it. I only saw fluid come out, and it wasn't aerated.

Also it says longest brake line first, which I already knew, but I went from the brake master cylinder, so I did this order:

Rear passenger, rear driver, front passenger, front driver.

It occurs to me now though that the ABS pump is on the passenger side, so should I actually have been doing:

Rear driver, rear passenger, front driver, front passenger

?

Also, if the engine is off the pedal firms up nicely after a few pumps, but as soon as I start the engine, it sinks a depressing amount. Does this fit with some air still in the system? I can't clamp the hoses off, they are braided. Also I don't have a vacuum bleed system so don't say "use vacuum bleed system"

-Ian

PS UK spec brakes

i used a self bleed system but was a tube with a slit and blocked at one end put into tub of fluid done the job. bleed mine passenger rear 1st then so on. did you prime abs pump by turning key while bleeding brakes. maybe air in abs pump

uk brkes front

jspec rear

ps you cant clamp the braided lines what about blanking off. or could you crimp further up the line

Get some washer hose, a 1 litre bottle and put a quarter of a litre of brake fluid in the bottom, and have the end of the hose in the fluid. Put the washer hose on the end of the bleed nipple. Crack the nipple off and get an assistant to slowly push the pedal 3/4 of the travel to the floor repeatedly. You'll see bubbles in the fluid at the bottom, and when the bubbles stop, close the nipple. Start on the NSR, repeat on the OSR, NSF then OSF. make sure the resevoir stays above the minimum.

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The brake pedal sinks to the bottom due to the brakebooster starts working. but yeah if there would be any air in the system it would probebly get even lower since the add in force.

I bleed my system not too long ago and i just had my mrs pumping the pedal slowly to get maximum pressure and then open the bleed valve repeted a few times. had the engine running while i did this to add the extra pressure.

did you just fill up the system with fluid or did you drain it first? if so you might want to bleed the master cylinder aswell.

DO NOT pump up pressure in the system, it's a SURE way to aerate the fluid with micro bubbles. In your case where the car has been used with air in the system leave it at least 12 hours for the micro bubbles to reform into bigger bubbles in the fluid. This video shows the correct technique. If you can find a pressure bleeder with the right cap fitting for the MKIV reservoir it's child's play but you may well have to make your own from a spare stock cap to modify. Old fashioned pedal bleeding will work just as well if you have access to a helper though. Press the pedal slowly, and release it slowly, they are going at it a bit fast in the vis (oooh err missus )

http://www.youtube.com/watch?v=8T7Qrz3zJno&feature=related

what about using a no return valve?

can be done with only one person that way.

You mean those spring loaded nipples? If the valve is the seat of the nipple, fine, but if the valve is in a tube pushed over the left open nipple you may find the threads leaky enough to draw air back in on the pedal upstroke. Plus you waste fluid as you can't see when all the air is out. Not sure if the valved nipples are still made, not seen any for years and the ones I have seen were bigger than the ones on a MKIV, diameter wise, which would give them more room for gubbins inside.

It seems they are still made, and they have addressed the leaky thread possibility nowadays:

http://www.speedbleeder.com/install.htm

I was referring to the valve in a tube like this- http://www.ebay.co.uk/itm/Brake-Bleeder-Clutch-Bleed-Bleeding-Tool-Kit-Valve-/270795518357?pt=UK_Motorcycle_Parts&hash=item3f0cabb195

I know this is for motorbikes and cheap, but i cannot complain, I have tested the valve in tube and two people method like the video.

I did the brakes with the engine running. Not sure if it's the best idea or not but they turned out good. More than likely overthinking the system in my head

I should add that I've a fancy tube for bleeding the brakes on my own - it pushes over the bleed nipple and then has a plastic fitting that kinda clamps it on the nipple. The other end goes in a bottle to hold the fluid.

I did the technique shown in the video on my second attempt to sort it, but I wasn't getting out the amount of fluid they were. I'm a fan of their environmental concerns with fluid disposal though

Perhaps I need someone with a heavier right foot as my glamorous assistant At least I got the wheel order right though, I think?

Get some washer hose, a 1 litre bottle and put a quarter of a litre of brake fluid in the bottom, and have the end of the hose in the fluid. Put the washer hose on the end of the bleed nipple. Crack the nipple off and get an assistant to slowly push the pedal 3/4 of the travel to the floor repeatedly. You'll see bubbles in the fluid at the bottom, and when the bubbles stop, close the nipple. Start on the NSR, repeat on the OSR, NSF then OSF. make sure the resevoir stays above the minimum.

 

Aha that's a good idea because it'll show me that air is actually coming out, I can do that with the gear I've already got, thanks It's going to have to wait a couple of weeks while I'm off on hol but then I'll give it a go!

The order doesn't really matter, to be honest. Have you tried just gravity bleeding them? You need to leave the cap loose on the MC, or off, and regularly top up. Do one nipple at a time. Forcing the caliper pistons right back in the bores will leave FAR less space for air entrapment. That often helps a lot. Don't forget the pedal will need a lot of slow pumps to push the pistons and thus pads back afterwards, I've seen loads of apprentices hit cars / walls and even drive across a busy junction because the forgot to do this....

Well, I'll try the "fluid in the bottle" first to see if air actually comes out. With someone else on the pedal, I can actually do this. Then I'll try the gravity bleed.

I've experienced the terror of no brakes after changing pads, I know what to expect fastest I ever came out my driveway, that was....

I'd get a vacuum bleeder

£20 on amazon

I'd get a vacuum bleeder

 

£20 on amazon

Do those not need a compressor to run? Pretty sure we would all have one if we had a compressor.

No you simply pump them by hand, no need for a compressor or an assistant

pressing the pedal up and down

Google vacuum bleeder and theres dozens of them and most are

hand pumps

No you simply pump them by hand, no need for a compressor or an assistant

pressing the pedal up and down

 

Google vacuum bleeder and theres dozens of them and most are

hand pumps

Sounds good, I had a quick look on amazon but couldn't see anything in the £20 range

Edit: Searched on ebay too, right up to £85 everything is compressor related. Do you have any links for these? Maybe I'm searching for the wrong thing "Vacuum bleeder"?

This one is £26.63 on amazon

Brake and clutch bleeder vacuum type by Jack Sealey

Worth getting imo, you could always rent it out to mates perhaps

Sorry this one needs a compressor lol

This one is £26

 

Worth getting imo, you could always rent it out to mates perhaps

That's the one there are loads of. Hooks up to a compressor via the nozzle on the end of the compressor gun

The one i used was a Mityvac fluid evacuator

Sorry for missleading info above i thought they were similar versions but yes they would need

a compressor but the Mityvac doesn't

The one i used was a Mityvac fluid evacuator

 

 

Sorry for missleading info above i thought they were similar versions but yes they would need

a compressor but the Mityvac doesn't

Can't find them for any less than £100 though, bit pricey for what it is.

I did the brakes with the engine running. Not sure if it's the best idea or not but they turned out good. More than likely overthinking the system in my head

I did mine the same way using a one man bleeding bottle...

It is a bottle and tube with a one way valve, just connect it up to the nipple, open it and pump till no bubbles are visible, bled perfectly, pedal is firm..

Was chuffed with that one cos it was the first time I did it ever!

My apologies for making an incorrect assumption on the vacuum bleeders, must

take more time and read all the info before typing next time

I've found a vacuum bleeder that appears to be a hand pump and is £40.

http://www.simsestools.co.uk/hand-held-vacuum-pump-brake-bleeder-kit-cars-p-154.html