Prawn and BigAls A3 Track Car

More progress last night :)

Final run from the Bias valve complete and clipped:



T piece mounted and everything connected up:



And the fire ext and nozzles all back in place and the rear lines clipped and complete:



Hardlines to the rear calipers should arrive today, so I'll adapt them this evening and fit those, then bleed some fluid through the system and see if it works before refitting the seats and fuel pump.

Edit: Order of tasks corrected because Erik pointed out it was the wrong way round :laugh:
 
Last edited:
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Feel your pain with the rear braided hoses. Forgot to document what I did but it was very similar apart from using rubber grommets to route the pipework cleanly through the beam.

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Do you have braided lines from the beam to the calliper then Mark?

I didn't find any available in the UK, so I've just gone for standard hardline / rubber flexi for now, it may well change if a decent alternative exists.
 
Yes. Think I got them from Matt Lewis Racing (MLR) about two years ago.


Same issue as you had with the unions being too big for the guide holes so I drilled them out and fed through, grommet just about slid over the caliper connection. Also had to modify the union bracket on the beam.

Tapatalk is being dicky and won't let me post pictures otherwise I'd show you what I mean.

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4e1e1d56ee78a2fc4f9d0c7161d2be0a.jpg


946358a5b25a8a1a4ee7d9365cee6200.jpg


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Prawn said:
I didn't find any available in the UK, so I've just gone for standard hardline / rubber flexi for now, it may well change if a decent alternative exists.
Click to expand...

Hose Technik (Forge) should be able to make you some braided ones to your specification, just need to tell them the length and what fittings you need on the ends. Usually done same day too so shouldn't have to wait ages for them to be made.
 
audi upgrades
I've used Hose Technik and the service was spot on for custom jobs.


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Another day passes, another set of mixed feelings!

I got home last night, feeling pretty keen to keep up momentum with the car.

I fitted the new rear lines:



It was fairly easy to massage the end to suit my new connection location:



This all had to be done in an 'inboard' direction, to avoid the pipe fouling on the bodywork at full compression.

I then got out the EZ bleed, and bled a litre of brake fluid through the system.

All 4 corners bled up really nicely, with a strong and even fluid flow from each caliper.

I then bled the master cylinder. All seemed well.

Time to press the pedal and see what happened.......

And that's where the trouble started :laugh:
 
So,

They bled fine. Went round the whole car twice.
Air on the first flush as you'd expect with brand new lines. Then crystal clear clean fluid with no air at all on the second bleed. Master cylinder set bled each time to be sure. ~20psi pressure on the EZ bleed.

I pressed the brake pedal.

It felt CRAP!

It didn't drop to the floor, it was obviously moving fluid and pistons somewhere, but first impression was very soft.

I pumped it a few times. And wasn't happy with the action at all, so went round the whole car and bled the whole lot again to be sure there wasn't an airlock or similar somewhere.

Pedal STILL rubbish.

It also sounded odd. It was as if I could hear 'fluid noises' as I pressed the pedal.

I applied a constant pressure to the pedal, and as I held the pressure on the pedal slowly sank to the floor under sustained pressure, as did my heart :bye:


I continued pumping at the pedal a good few times more, then went over the whole car again checking every single fluid union. Not a drop evident at any of my joints, or any of the calipers.

It was then I noticed there seemed to be brake fluid on the bottom of the servo. Very strange :huh:

It was almost as if fluid was leaking out from inside the servo. How bizzare.

I cleaned the servo off totally, then pumped the pedal a few more times.
The fluid level in the reservoir seemed to be going down very slightly, but nothing visible on the servo immediately.

5 minutes later though, and the servo was damp again.

I removed the MC, and whilst it's very hard to say for sure, it LOOKED like there was evidence of fluid on the plunger rod on the back of the master cylinder.

Current thoughts are that my brand new Pagid master cylinder from ECP is faulty from new, and is bleeding fluid past the seals and leaking into the servo.

Second issue is that it's then leaking out of the servo, suggesting that the servo isn't as air tight as it really should be!

Im going to speak to ECP about a return on this dodgy MC, and also grab my spare servo from storage and have a think about fitting that. I might rig up a DIY pressure tester to check both servos before attempting any work.

Has anyone ever removed / changed a servo? It looks like the bolts are accessed from inside, and I can't imagine they're going to be too enjoyable to reach at all!

Argh. Car. Why do you treat me this way?

I won't be beaten though. Never give up, no matter how much you want to.

I think I've earnt another beer this evening :racer:
 
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Reading all this with interest as ill be re-plumbing the scirocco's brakes over winter.

The servo has to vent it's vacuum somehow after you release the pedal, so won't be a completely sealed unit, and will leak fluid out if it's filled up by a dodgey master cylinder. I think this is usually into the cabin, so may not be what you're seeing, but it's not necessarily knackered just because the fluids finding a way out.

Good luck with it!
 
That's an interesting thought Robin :) I had assumed the servo should be a totally sealed unit.

I've just picked up my spare servo, which despite a slightly corroded centre that I can clean up, looks to be in much happier condition generally.

I'll look inside and see how easily accessible the servo securing nuts are, and if it's not too tricky I'll change them.

I'm inclined to think my servo should be OK, as it's certainly never caused me any issues before.

The master cylinder though, I'm pretty confident is at fault.
 
Generally all rock out from the same factory.

Servo aint too bad, just the 4 bolts that hold it in from behind the dash.

Did you bleed the MC last? had a few where the pedal was crap but then bled the MC last and it firmed up.
 
Yup, always bleed the MC last Chris, without blowing my own trumpet, I'm somewhat experienced in the braking systems on these, having been through SO many issues and tried so many setups over the years.

Had a bit of a result today though, thanks to @mjr901 Mike and the ASN parts request!

Mike came in a whopping £50 cheaper than ECP for a genuine master cylinder, and that's WITH the ECP discount code for black friday. Without the codes there's almost £90 price difference.

That's twice now I've had amazing service and value from the ASN parts request. I'd urge people to use it more often.

When dealer supplied genuine parts are coming in cheaper than discounted ECP prices, it's really a no brainer!

Genuine MC en route to me Friday. Spare servo collected. I'll replace the whole lot then see what's what!
 
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Madness, that's what it is. Recently I wanted a cruise control stalk for my Audi. 140 from local dealer, 74 delivered from Germany. Spoke to Stafford Audi and they matched the price of 74. Result. Pay's to haggle.
 
Chris90 said:
Servo aint too bad, just the 4 bolts that hold it in from behind the dash.
Click to expand...


You're dead right Chris :)

Just checked it out and the 4 servo bolts are way more accessible than I thought they were.

In my mind the servo was much higher up in relation to the dash, but it's actually fairly low down and I can access all 4 bolts easily enough :)

Will get the servo swapped over and the new master should arrive on Friday :) fingers crossed that'll be the end of it and I can get on with the engine work!
 
I remember when I was at college many moons ago learning about master cylinders our tutor mentioned not to floor a brake pedal too hard if there is no fluid in the system or when bleeding. Potentially the piston seals can flip over and then it will start to leak.

Not saying you did that, but something to keep in mind.
 
Chris90 said:
Generally all rock out from the same factory.

Servo aint too bad, just the 4 bolts that hold it in from behind the dash.

Did you bleed the MC last? had a few where the pedal was **** but then bled the MC last and it firmed up.
Click to expand...

same as Bosch maf's from euro?
LMAO
 
HTC said:
I remember when I was at college many moons ago learning about master cylinders our tutor mentioned not to floor a brake pedal too hard if there is no fluid in the system or when bleeding. Potentially the piston seals can flip over and then it will start to leak.

Not saying you did that, but something to keep in mind.
Click to expand...

Very good advice Kev, and still 100% relevant today.

That generally applies to older cylinders where debris can build up in the unused end of the bore, which then causes the seal to flip as it 'picks up' on the debris when pressed right down.

I think it could absolutely apply to a brand new dry cylinder as well though.

I'm always very careful never to push to the floor, and bleed with a pressure bleeder so the pedal wasn't touched until after it was bled, but there's nothing to say that the plunger wasn't pressed by someone else at some stage between manufacture and me collecting it from ECP :(

I'm very impressed by the no quibble returns policy from ECP at least. I told them it was faulty. They didn't question me, and gave me a full refund immediately.

Fingers crossed the genuine one from Mike sorts the issue

badger5 said:
same as Bosch maf's from euro?
LMAO
Click to expand...

:laugh: :laugh: :laugh:
 
audi upgrades
When as a business (or even an individual for that matter) you have a slew of MAF's that are either DOA or lasting days rather than months from a one supplier but not from another then you tend to not trust said supplier of what would appear to be exactly the same product...

<tuffty/>
 
Its arrived!



Ordered at 16:30 Wednesday, @mjr901 didnt even have it in stock at the time, yet it still arrived with me at 10:30 Friday.

Very impressive service indeed :)

I've also picked up my spare servo.

The perimeter is in far better condition than the current one, with no corrosion at all, but the centre mounting ace has obviously been subject to corrosive brake fluid in the last and has suffered a little.



I'll clean it back and repaint it, then attempt to bleed the brakes up again and see where I stand!
 
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Glad it's arrived!

Good luck and don't forget to give me a ring in the future! :)

Cheers

Mike
 
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So, the car that loves to fight me continues to do so!

4 servo bolts removed with relative ease. Top right was a little fiddly, but over all ok.

Then of course, we have the impossiclip!



Now, aside from a special tool that's about £50, to release a £6 clip, I'm told there is a knack to releasing this, using all manner of screwdrivers in strategic locations, but access isn't helped by my rollcage cage door bar, and frustration probably played its part here too.

Try as I might, I absolutely could not get the clip to release the push rod!

I sought advice, and the official line from those who've removed them before is to break the clip for easy removal, and replace with a new clip.

Even that is proving difficult!



So after lying on my back for an hour in the footwell, getting dirt and grease in my hair, and severely scratching my glasses on my brake pedal, I gave up last night.

This morning I'm going at it with a hammer.

New clip comes into tps on Tuesday morning.
 
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The impossiclip is off!

Woooohoooooooo :laugh:

New servo cleaned and painted too
 
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Where does time go?

Argh.

The new Impossiclip is here, and will be fitted shortly with any luck.

I've also stripped the head of it's 4 standard valves.

I looked at re-fitting the 4 supertech valves, but I honestly can't see how on earth I'm going to manage to get the collets in place!

the centre valves are SO far recessed into the head, that the 'window' on the valve spring compressor almost totally vanishes when the spring is compressed.

This doesn't look like a fun job at all!
 
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Prawn said:
Where does time go?

Argh.

The new Impossiclip is here, and will be fitted shortly with any luck.

I've also stripped the head of it's 4 standard valves.

I looked at re-fitting the 4 supertech valves, but I honestly can't see how on earth I'm going to manage to get the collets in place!

the centre valves are SO far recessed into the head, that the 'window' on the valve spring compressor almost totally vanishes when the spring is compressed.

This doesn't look like a fun job at all!
Click to expand...
I ground my spring compressor down for access
 
Prawn said:
Where does time go?

Argh.

The new Impossiclip is here, and will be fitted shortly with any luck.

I've also stripped the head of it's 4 standard valves.

I looked at re-fitting the 4 supertech valves, but I honestly can't see how on earth I'm going to manage to get the collets in place!

the centre valves are SO far recessed into the head, that the 'window' on the valve spring compressor almost totally vanishes when the spring is compressed.

This doesn't look like a fun job at all!
Click to expand...
Its not a fun job, it's why I always get them . I must have been bad in a previous life,LOL

Grease the grooves, small magnetic screwdriver and an open compressor tube thingy is my chosen method

EDIT, a compressor like this.
http://www.ebay.co.uk/itm/LASER-VAL...653576?hash=item543f252c08:g:nGoAAOSw5cNYNcTF
 
Thanks for taking the advice guys.

I am definitely TOO defeatist at times.
I've been really dreading this job and fairly convinced I wouldn't be able to do it.

We offered the compressor up late on Tuesday night, and decided that it looked near on impossible.

This evening, we approached it much less tired, and a little more open minded, and against all my prior thoughts, we had all 4 valves installed within an hour!

Marks tip of grease worked a charm, and thanks to tuffty for answering about a thousand questions over the last few days too :laugh:

Fingers crossed I'm back into known territory again now, and it's just a case of putting the hours in to get it closer to completion.

Watch this space!
 
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