oneohtwo's VR6 - New Engine!

[Dox 22]

1 hour ago, MJA said:

That's a good trick and I also found out recently that if you wedge the brake pedal down and take off say a brake calliper or flexi no fluid will leak out. Still needs bleeding but generally only the corner you're working on. 

That’s correct, the pistons travel past the inlets stopping feed from the reservoir so the reservoir can’t empty. 
 

you need to pressure the system with the pedal to purge air, so wedge down hard

[oneohtwo 8]

4 hours ago, Dox said:

An old trick is to wedge the brake pedal down overnight, any air trapped near to a flare / fitting will leak out (where a fluid won’t).

Ah, interesting... I might give this a try.

Also noticed the techy managed to spill a bit of brake fluid on the top of the strut housing and it's nicely eaten all the paintwork away. Only repainted that area last year.

[_Matt_ 26]

1 hour ago, oneohtwo said:

 

Also noticed the techy managed to spill a bit of brake fluid on the top of the strut housing and it's nicely eaten all the paintwork away. Only repainted that area last year.

That is super annoying after all your efforts and annoying it is common place with garages too. I am always having trouble when i take any of my cars places - no one treats them as well as we do. 

[ABV-VR6 12]

Well done! Sucks for the paint though... 

I'm in the process of bleeding my new brake system and what Vince told you is right. Look up "bench bleed a master cylinder" on google, there's many way to do it and I'm pretty sure that's what you need to do, specially after what was done and didn't fixed it... 

[ABV-VR6 12]

You need a kit like this... 

[fendervg 29]

You need a kit like this... 

I just stick a Sealey vacuum pressure bleeder on and bleed the lot - never had any issues, and makes it a one person job. They are not that expensive.

You can gravity bleed the clutch master as it sits lower than the reservoir.

[Dox 22]

There are lots of previous posts re bleeding these up after the hydraulics have been drained, many have found the pedal to improve after a couple of hundred miles or so, especially after friction material and disk replacement at the same time. Obviously you are aware of the long pedal and should drive accordingly. I used 2L of fluid after replacing my ABS pump and still had a long pedal, a second bleed after 200 miles forced little air out.

 

Don't compare these aging systems with modern cars, there is no comparison, they do stop, they just need more pedal pressure

[fendervg 29]

2 hours ago, Dox said:

There are lots of previous posts re bleeding these up after the hydraulics have been drained, many have found the pedal to improve after a couple of hundred miles or so, especially after friction material and disk replacement at the same time. Obviously you are aware of the long pedal and should drive accordingly. I used 2L of fluid after replacing my ABS pump and still had a long pedal, a second bleed after 200 miles forced little air out.

 

Don't compare these aging systems with modern cars, there is no comparison, they do stop, they just need more pedal pressure

^ this be true - no matter how often you bleed and what you replace, this era of cars will still fell a bit softer to brake, with some travel, compared to newer models. It will kick in nicely once you put the foot down. This is partly the age of the technology, and also design - there is a limitation on how leverage is exerted at the pedal/mc/servo, and this is a physical fact that can't be changed - you'll find most newer cars have much more mechanical advantage here. A few people have tried with the Mk3 system, which is a little better, or even using a Mk4 pedal box and servo, but this is a lot of work.

People get disappointed after spending lots of money on new master cylinders, callipers, pads and discs and a full bleed because it doesn't break like Mk5 Golf, but it never will, and you tend to get used to it. For what it's worth, two things that are often overlooked are weeping seals on the master, and an ageing servo and piping that don't maintain proper vacuum.

[Tigerfish 10]

There are lots of previous posts re bleeding these up after the hydraulics have been drained, many have found the pedal to improve after a couple of hundred miles or so, especially after friction material and disk replacement at the same time. Obviously you are aware of the long pedal and should drive accordingly. I used 2L of fluid after replacing my ABS pump and still had a long pedal, a second bleed after 200 miles forced little air out.

I found the same. After I fitted the the 288’s and replaced the front to rear brake pipes. Was totally disappointed with the feel, but they seemed to dial themselves in eventually. They are brilliant now.


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[tonedef 8]

I got mine spot on last year, Teves 20, 288s and Mk4 rears. Had the callipers at Bigg Red over the winter and can’t bleed them up for trying now! It’s not the first time I’ve been frustrated by Corrado brakes in the last 26 years, they’ll come good given a bit of time!

[oneohtwo 8]

Yeah, I always remember the brake pedal had a relatively long travel before, and the only cars I have really been driving since are new hire cars where the brakes are only ever on or off! Have to say I don't fully understand why they are so sensitive in new cars - I get it makes emergency stopping a bit easier, but a little bit of pedal travel wouldn't go amiss surely? Would make for smoother driving in traffic. Electric parking brakes are another innovation are don't entirely see the benefit of.

Anyway, I do know the master cylinder hasn't been bled and Vince says that needs to be done, so I will get that done. At least then I will know everything that could be done has been, and I can live with whatever the brakes are like after that. Hopefully will improve with time a bit as well.

[ABV-VR6 12]

I do think it will get better after, you're on the right path... Then you'll brake the new rotors and pads and overtime it will be better... 

[oneohtwo 8]

Hmm, I went for a short drive yesterday and the ABS light came on mid drive. When I stopped and and started the engine again it stayed off. Something definitely not quite right... Well it's going into the garage Thursday anyway.

[fla 9]

did you manage to scan it for error codes?

[Dox 22]

If it’s in conjunction with brake application suspect pedal sensor, if faults when the engine bay is cold but stays good once warmed suspect dry solder  joints on the pump

[Cressa 44]

4 minutes ago, Dox said:

If it’s in conjunction with brake application suspect pedal sensor, if faults when the engine bay is cold but stays good once warmed suspect dry solder  joints on the pump

100% I'm with Dox. Happened to me last year and I was given the same advice. Easy fix too for a Corrado

[oneohtwo 8]

Haven't managed to scan as my VCDS cable is buried in a moving box somewhere!

9 hours ago, Dox said:

If it’s in conjunction with brake application suspect pedal sensor, if faults when the engine bay is cold but stays good once warmed suspect dry solder  joints on the pump

I think the light came on straight after I had been holding the brakes on for a few minutes waiting at a junction. I didn't see it come on exactly, but it was pretty soon after the junction I saw it, and it definitely wasn't on when I set off. It didn't go off after the engine had warmed up so I guess that suggests the former? It only went off (or rather didn't come on) after I switched the engine off and back on again. 

[oneohtwo 8]

Been for another spin and light was on from cold. After engine had warmed up I turned off and on again and light went off so sounds like actually it's the dry solder joints. I saw a bit about  this in the wiki section so I guess that's the fix?

It's in the garage now so not sure what they'll make of it.

[_Matt_ 26]

I did little guide on my corrado thread on how to repair the brake pedal sensor. Also Stealth will do it if you remove and send to them as well.

[Dox 22]

If a warm bay keeps the light off its more likely to be the solder joints on the control board on the pump IMO (heat from the exhaust expands the joints on the pump as its bolted to the bulkhead).

Saying that the pedal sensor is 25+ years old and the system would benefit long term for having these joins reflowed anyway?

I bought my car with the light on permanently, the car was ex Isle of Man and had never had an MOT in its 15 years. 

Scans revealed a wheel sensor fault, Inlet / outlet faults / pedal position sensor fault.

I swapped the wheel sensor and got the car through its first ever MOT.

Then came the intermittent faults, light on when the bay was cold, but restarting when hot would keep the light off - I swapped the pump (it was a MK3 pump with a different part number) and the light went out on start up when cold as it should.

Then came the random light on under braking, replaced the pedal sensor with a re-conditioned one purchased off Emu off the forum.

Since all the above the Wheeler dealer program aired showing the circuit board fix and other forum member kindly posted their pedal sensor fixes.

The whole set up is problematic and age is affecting the system too (water ingress into the ECU is also an issue - rusty leaking windscreens), wiring doesn't seem to be as problematic as the hardware but again age and constant fiddling with connectors wont help long term.

[tonedef 8]

I don’t know if anyone else has had the same as I did. The lamp on at cold and off if restarted when warm along with reading wheel speed and valve faults was much the same as I’ve read countless times. If however I’d warmed up and reset the lamp, it would come back on without fail at 74mph, something I’ve never seen mentioned elsewhere?

It’s all been stripped out though now as I gave it up for Teves 20, I can’t recommend that enough as it appears to just work without any drama. It is a bit of a faff to install mind!

[oneohtwo 8]

Can't help with that one I'm afraid. I didn't get up to 70 in the times it wasn't working.

Got the car back from the garage and the brake pedal is much, much better, I think like it should be, and the ABS light issue seems to have resolved itself along with that, which is good news. Although not sure what was the cause of it. 

Apparently the garage bled it all using the diagnostics tool/PC. They didn't find the bleed nipple on the brake cylinder either but suggested it wasn't needed because the PC had done it, although I didn't think the Corrado system used a PC to bleed? Slightly annoying as now I have in the back of my mind that it hasn't been done, and could it still be better?! Fine for now anyway.

The next small niggle is that I seem to have a small coolant leak, which I think I have traced to the ECS alloy crack pipe - I think where it slots into the thermostat housing. Annoying in that there's not much I can do about that as there's nothing to tighten; it just slots in. I was hoping that after having done all the rebuild I wouldn't have to be checking and topping up fluids before every journey!

[fendervg 29]

What can happen with the crack pipe is that the new o-ring seals get nipped or damaged during installation, usually on the water pump/block side, but I see it's on the stat housing from your post - could be worth replacing the seal but it's a lot of hassle. Also sometimes the leaking coolant will make it's way far from where it is actually leaking from.

As far as I know UK Corrado 2.9 cars with original ABS never used diagnostics to bleed the pump - it's not possible, and not available as an option in VCDS. This was only for the later OBD2 2.8 cars with a different ABS setup where the pump was integrated  into the master cylinder and reservoir - possibly also on LHD Euro and US cars.

[easypops 8]

I couldn’t get my SS crack pipe to seal at the block either, where as the new oe one sealed first time, which is why it’s still there 

[ABV-VR6 12]

Glad to hear your brake system is fixed! I too wanted the metal crack pipe but many guys discouraged me from it for this exact same reason, it won't seal properly... I then decided to steer away from it and go with the oem one.