High pressure in cooling system

[rum4mo]

Well when my friend with the SAAB 96 moved it around a bit and then into his garage, after it had not been moved for 24 months, it had "no brakes", so for the first time in his life, he bought a Gunsons Easy Bleeder (I have bought 3 of them over the years, get a new one when I can't get the seals to seal), the very old fluid that was forced out was dark brown, not very clever for someone trying to keep an old car running - maybe now he will change the fluid in his SAAB 9-5 - if I annoy him enough! The reason that I did not get round to using my pressure bleeder is, he is a messy person and would lose some or most of the extra things I keep to bleed brakes, like longer hoses and suitable containers to collect the old fluid in - and I would not expect that new Gunsons kit to get cleaned out, dried and kept in a dry area ready for its next use!! His original plan was to just fill the bottle with fluid, connect to any tyre with air in it and then open the bleed valves - with an old baking tray somewhere near by to catch some of the fluid - but he has just painted his newly built garage floor red with proper paint, so that did not seem correct!

 

Replacing brake fluid in modern cars with ABS, I've always used a pressure bleeder, ie Gunsons and made sure the system, or at least up to the ABS block is filled with fluid. even when replacing hoses/callipers etc, so far over 27 years of running cars with ABS, that has worked okay.

[KenONeill]

@rum4mo - A pressure bleeder is ok as long as you don't use more than 15PSI; it's safer to use a vacuum bleeder with ABS though.

[rum4mo]

Oh I hope that I am "long enough in the tooth" to know not to use high pressure with these things, for years I've just used a modified Hozelock  garden sprayer as a pressure vessel - and it has a blow-off valve that is set a bit lower than that - used to use it as a pressure source fitted in line to another Hozelock garden sprayer that had its pump end capped off, when applying Waxoil - these sprayers were bought at end of season clearance time basically for next to nothing - and still working okay, I think that it was a metal tractor valve that I fitted into the end of the outlet hose.

[sepulchrave]

3 hours ago, KenONeill said:

@rum4mo - A pressure bleeder is ok as long as you don't use more than 15PSI; it's safer to use a vacuum bleeder with ABS though.

 

Utter nonsense, guess what the pressure in the system is whenever you press the brake pedal, go on, guess.

[TMB]

2 hours ago, sepulchrave said:

 

Utter nonsense, guess what the pressure in the system is whenever you press the brake pedal, go on, guess.

 

I think it's more so that the pressure bleeder doesn't explode. My Eezibleed states a max of 20 psi.

[sepulchrave]

Just now, TMB said:

 

I think it's more so that the pressure bleeder doesn't explode. My Eezibleed states a max of 20 psi.

 

Mine doesn't, I just connect it to a front tyre, my fronts run 33 PSI.

Dudes, I've been using an Eezibleed for 35 years, I just connect it to a front tyre, I always have. What car only runs 20 PSI in its front tyres, are they suggesting you let the tyre down before connecting it?

That's not what Ken was getting at, it's about the 'flipping a seal in the ABS block myth', how the hell are you going to flip a seal with an Eezibleed at 30 PSI if the brake pedal can supply fluid to the calipers at 1000 PSI?

Mindless madness.

[TMB]

Yes I always let my tyre down to 20psi. Just obeying the Eezibleed instructions - they don't write them just for a laugh. However, I agree that you won't flip a seal in the brake system using higher pressure.

 

Edited 15 September, 2017 by TMB

[sepulchrave]

I'm not suggesting that the instructions are wrong, merely MASSIVELY over-cautious. My (very) old kit does not contain these same instructions so I've never worried about it since I've never had a problem in all the years I've used one.

 

Maybe someone in the states successfully sued them and they changed the instructions although I'm not clear how 33 PSI might be life-threatening compared to 20 PSI. Any ideas?

 

It's really basic, I'm trained to ask questions if something doesn't make sense, I can't unlearn that training and this doesn't make sense.

[TMB]

Mine is years and years old too and it says 20 psi. Don't get all upset though dude.

[sepulchrave]

1 minute ago, TMB said:

Mine is years and years old too and it says 20 psi. Don't get all upset though dude.

 

I'm not, this minor rant was a reaction to Ken's mythological guff about the ABS block and vacuum bleeders, which are designed for convenience and speed but otherwise do exactly the same job.

[Breezy_Pete]

Interestingly, the official erWin instructions for bleeding the ABS blocks using the prescribed pressure bleeding system (VAS 5234) say words to the effect of "adjust the pressure to at least 2 bar, any less than that and  successful bleeding can't be assured".

 

I've always used the spare tyre with my eezibleed, at 15-20 psi, but I've never had any air in an ABS block to try to get rid of.

[Torbo]

I got some piston rings to day. One "crome", one black and tree oil rings. 

Should I install the chrome ring at the top of the piston? There is no TOP-marking on it...

The black ring is marked TOP, som thats normal..

 

Sylinders is waiting for me i a garage near me, and some gasket is waiting  at a neighbor near my garage. So there rest is logistic ...

And some oil on my fingers. 

I will take the buttom off the engine first and lock for water for examine. When the head is of, its to late, because water rests can go from the loose cylinders inside.

 

 

[sepulchrave]

37 minutes ago, Torbo said:

I got some piston rings to day. One "crome", one black and tree oil rings. 

Should I install the chrome ring at the top of the piston? There is no TOP-marking on it...

The black ring is marked TOP, som thats normal..

 

Sylinders is waiting for me i a garage near me, and some gasket is waiting  at a neighbor near my garage. So there rest is logistic ...

And some oil on my fingers. 

I will take the buttom off the engine first and lock for water for examine. When the head is of, its to late, because water rests can go from the loose cylinders inside.

 

 

 

I would install the chrome ring as the middle and the black as the top ring, a chrome ring will not bed in as quickly as a plain ring and the cylinder will leak compression badly otherwise.

 

I'm not saying that's the case, it's just what I would logically do.

[Torbo]

I hav thought the same. But I think the chrome ring shall be in top to endure more heat from burning. 

Other engines has the chrome on top, but the black casting ring can give faster adaptation.

I have to think twice here...

 

[Torbo]

some picture of the new piston rings: - The ends to see the difference 

[sepulchrave]

Dude, that plated ring is not Chrome, it's a PVD coated steel ring and it's definitely the top ring because it's much more expensive than the black plain cast Iron ring. It has no markings because it's symmetrical and can be fitted either way round.

[Torbo]

3 hours ago, sepulchrave said:

Dude, that plated ring is not Chrome, it's a PVD coated steel ring and it's definitely the top ring because it's much more expensive than the black plain cast Iron ring. It has no markings because it's symmetrical and can be fitted either way round.

 

Thanks! It look like a top ring to me to. The black ring has top marking. Hope I can fix the engine next weekend. No I have some other health challenges... Hope the service on me is ok/repaired wednesday !?

[KenONeill]

On 9/15/2017 at 20:17, sepulchrave said:

 

Mine doesn't, I just connect it to a front tyre, my fronts run 33 PSI.

Dudes, I've been using an Eezibleed for 35 years, I just connect it to a front tyre, I always have. What car only runs 20 PSI in its front tyres, are they suggesting you let the tyre down before connecting it?

That's not what Ken was getting at, it's about the 'flipping a seal in the ABS block myth', how the hell are you going to flip a seal with an Eezibleed at 30 PSI if the brake pedal can supply fluid to the calipers at 1000 PSI?

Mindless madness.

OK, where did I say that? Oh and whether you believe it or not, it's an established fact that 30PSI (relative) can be enough to push an air bubble into the ABS block.

[sepulchrave]

4 hours ago, KenONeill said:

OK, where did I say that? Oh and whether you believe it or not, it's an established fact that 30PSI (relative) can be enough to push an air bubble into the ABS block.

 

I don't believe it at all, where's the air going to come from, you're forcing clean fluid from the reservoir at the very top of the system right the way through to the bleed nipple on the backplate, this is THE SAME as putting your foot on the brake pedal to pull fluid from the reservoir only the pressure is much lower.

[Warrior193]

On 9/15/2017 at 17:22, sepulchrave said:

 

Utter nonsense, guess what the pressure in the system is whenever you press the brake pedal, go on, guess.

The reason why you should not use high air pressure in these brake bleed systems is because there is a risk of introducing moisture and air bubbles into the nice clean fluid.  Compressed air often contains water vapour, which can be released into the brake fluid.   

Edited 18 September, 2017 by Warrior193
Explanation

[rum4mo]

I understood that the main reason for not using too much pressure with at least some VW Group cars was that the reservoir might start leaking at the join in the moulding, remembering that the reservoir is only ever under pressure when the brakes are being bled.

[sepulchrave]

2 hours ago, Warrior193 said:

The reason why you should not use high air pressure in these brake bleed systems is because there is a risk of introducing moisture and air bubbles into the nice clean fluid.  Compressed air often contains water vapour, which can be released into the brake fluid.   

 

Please read properly further up, I'm only suggesting that using air from a fully inflated tyre at 33 PSI is also fine, I'm not suggesting connecting to an airline at 100 PSI for crying out loud.

[Warrior193]

2 hours ago, sepulchrave said:

 

Please read properly further up, I'm only suggesting that using air from a fully inflated tyre at 33 PSI is also fine, I'm not suggesting connecting to an airline at 100 PSI for crying out loud.

But there is also a high probability of excess moisture in the air from a tyre - using a pressure pressure higher than recommended by the manufacturer is very likely to cause a problem.

[sepulchrave]

1 hour ago, Warrior193 said:

But there is also a high probability of excess moisture in the air from a tyre - using a pressure pressure higher than recommended by the manufacturer is very likely to cause a problem.

 

The air doesn't ever enter the braking system, it simply pushes on the surface of the brake fluid in the eezibleed bottle forcing the fluid up the pickup, it isn't bubbled through it, how would moisture even enter the system?

 

It's a brake-bleeder not a bong, If something doesn't make sense then it's not true. This doesn't make sense.

[Torbo]

A little break. Her is my new cylinders and pistons to mine Dauphine.  And one of my old with bad surface and my cat... Have not got the Fabia-sylinders yet. If I get time I will put in a wedge to forward the cam 3 degrees to get more torque in low rpm. ?