Brakes Fixed, Engine Almost Fixed!

I gave my new Eezibleed a go and got a whole load of air out the brakes that I didn't know was there. Works pretty well, if you don't know what one is basicaly you have a bottle with two hoses, one connects to your brake reservoir, the other to a tyre at 20psi, then you just go round and open the bleed nipples and the fluid comes out as if someone is stood on the brakes.

Unfortunately I left the rear passenger caliper off the disc when I connected the eezibleed so the piston popped out and fluid everywhere. Whoops!

Reassembled and had to start all over again with the bleeding. I put about 5 litres (the same litre, 5 times!) through the rear brakes before I got rid of all the trapped air, it takes a long long time!

I was a bit concerned that the brakes didn't feel the same as in our "normal" car and got some advice of the cobraclub forum, the pedal should go hard after a few pumps with the engine off but this wasn;t the case on the cobra. There's a non-return valve from the servo to the inlet manifold and I was advised to check this was the right way round. I was pretty sure of this but I had a look anyway, turns out out the jubilee clip on the hose wasn't done up so I think I had a vacuum leak. Nipped it up, finished the brakes off and started the car, would you believe it's now a lot smoother! Here's the offending bit of hose coming from the brake servo:

I had my friend Max round and we went for a drive to warm it up before having a play with the idle mixture and immediately it was obvious the car was running a lot better. It still bucks a bit but now only below about 1800 revs whereas before anything below 2200 it was kicking and surging. We had it cruising at 1800rpm in 5th nice and steady. I had a quick refresher in carb operation from Max, at normal road speeds to maintain 50 or 60mph in 5th is such a small throttle opening its completely dominated by the idle circuit. 

We checked the idle mixture after our warm-up drive and couldn't get it any better than the settings I already had but we surmised that it needed a few miles for the plugs to clean up after probably being fouled by the previous mega-rich mixture before the performance would improve. My last vacuum reading was 11in.hg and the needle was waving around almost +/- 1in.hg. After disconnecting and reconnecting all the vacuum hoses, it now read about 11.5 and was just bobbing gently +/- 0.25in.hg. Much, much smoother! 

Another quick job, we checked the timing. I knew it was at about 32deg all-in (3000rpm) but I wanted to know for reference what the idle timing was, its 14deg. The car won't start with any more initial advance, it kicks back against the starter.

So, the engine is running a lot better, not quite perfect as I'm sure it could be smoother at really low revs but smooth running down to 1800 is good enough for now, at least now I can do 30 in 3rd, 40 in 4th and not get thrown out of my seat.

Going back to the original topic, the brakes are now unbelievably good. The first mile or so of our initial warm-up drive were down a very quiet dead end back road where I did some hard stops to check braking performance. It will quite happily lock the front wheels from 50mph with a good hard stab at the pedal, the front right locked first but I expect a tweak to tyre pressure will balance things out. I've never had a car with such good brakes so its going to take some getting used to but my collarbones hurt from pulling against the harness!

All in all, a very good day, saw a few other nice cars around, corvette c5 gave us a thumbs up, saw a very nice Aston DB6 at the petrol station, had a brief chat with the owner. I think I saw an exige pass the other way but he was driving quite *ahem* enthusiastically (and so were we!) so it was a very brief meeting.

Also, the roads were dry enough to get a fair bit of full throttle and finally managed to get up to proper operating temp. Oil was just over 90deg instead of the 80odd that I was all I managed in the ice/frost, managed to get the exhausts properly hot for the first time too, passenger side was popping a bit on the overrun so it may still be a tiny tiny bit rich on that side.

Also also, may have set another car alarm off simply by driving by hehe : )

Handbrake

We were a bit apprehensive at fitting the handbrake as the forum is full of posts about people having trouble with it. The rear cables went on easy enough, bit fiddly with the clevis in each hub but not too bad. Its worth saying that the handbrake components in the hub came fully assembled and all I've done is just pop the rear brake disc over the top and  hook the cables on so we have missed out on a lot of the difficulties that others have described.

Right, handle on:

The cable then routed through the bulkhead as low as possible whilst still clearing the chassis lurking behind. The front cable then routes round to the half moon thingy.

I pulled the cable as tight as possible on the threaded section on the equaliser above so all the adjustment was taken up at the handle. It was then a case of adjusting away (easy with no seats) with Naomi turning the rear wheels by hand until the handbrake shoes grabbed. The IVA manual says the handbrake must hold the car on 4 clicks. As the car was in mid air we don't know if it will hold it but you can't turn the wheels by hand. Not the same as parked on a slope I know, but still it would appear to work. The IVA manual doesn't say how you achieve 4 clicks. I had to straddle the handle with one leg outside the car and pull like a mad person.

Brake Servo Heatshield

Its a brake servo heatshield. Not much else to say other than its 1mm thick ali sheet with some rubber u-channel on the edge to tidy it up. It's folded in two places and goes all the way under and around the brake servo. We realised immediately on fitting it that the bracket could have been hidden on the other side, but by that point it was almost midnight and we couldn't care less.

Ready for Engine

Did a little bit of work to prepare for the engine coming, made a bracket for the brake fluid reservoir and plumbed in the hoses on the low pressure side. The clutch is on a separate system with its own reservoir and looking at it now I think it may be in the way of the engine so I've left some slack on the hose and will finish it later. Also (although not in this picture) added the wiring to the pressure switch that does the brake lights.

Brake Pipe securing

Almost finished of securing the brake pipes. As you can see below the newly painted stealth matt-black brake servo is attached through the footwell bulkhead to the pedalbox. The clevis pin is the wrong size but that's not hard to sort. (beats £150 from Dax anyway)

Attaching the p-clips to the wing was made simple by the wonder of rivnuts. I cant believe I've only just discovered them. Rivets, with a thread in the middle! Who would have known?! Clearly in that picture there is some more clipping to do along the chassis but that's for another day. Also note my shiny new brake master cylinder (£18, cant remember where from) is also fitted and all solid brake lines are fixed in. Also I admit the brake lines themselves aren't perfect but I don't have a proper pipe bender and elected to use sockets and other handy round things. At least this bit of work is done now and we are at last making progress

Brakes Part 2

First job, front drivers side brake pipe

Right, that was easy. Now the rear.

3 way union jobby put up above the diff, line from the front comes in from underneath then splits left/right. Bit fiddly this, can you guess which was the first one, and which was the much-improved-from-experience second attempt?

Might do the left-hand one again. All thats left to do is the long run from front to back, which will roughly go like this:

Unfortunately my £9.99 Argos drill had seen enough for one day and tomorrow the Micra is having clutch surgery so no cobra progress for a couple of days.

Update 05/06/13 I've swapped the 3-way union for a 4-way one so I can add a centre bleed point as the union is quite high and looks a likely place for air to get trapped.

Brakes Part 1

Right then, time to actually drill into the chassis (eek!). I got the Dax brake kit with the chassis which comprises copper pipe (3/16 or 5mm OD I think) with braided flexi hose to get to the calipers. The pipes are pre cut the correct length if you follow the suggested route in the manual. I have heard stories of having to cut down pipes to fit, or including an "engineers loop" so we will see how it goes.

The first one I'm fitting is the front passenger side. Luckily I was looking through my archive of research photos and was reminded that the steering rack passes through in the region of the brake fittings so the steel tube in the photo below is my representative steering rack so I remember to work round it. Quite a complicated route to begin with but it got easier. I used a fan heater to gently warm the pipe for half an hour but it wasnt really necessary, it bent really easily around a 3/8 socket.

First I got some medium duty garden wire to plan the route but again, this wasnt necessary and I just got stuck straight in.

Steering rack neatly avoided, now up the other side and out with the masking tape before drilling and tapping for p-clips. (No budget nylon clips here!)

Thats the difficult bit over with, now just one more bend then the rest will be left coiled up for now as there is no brake master cylinder to fit it to.

Now to drill, tap and p-clip, remembering max 300mm between fixings. I'll put another one on the diagonal bit on the left chassis member as by string round all those bends its just over 300mm

Well that wasnt so bad, bit nervous about finally drilling into the precious powder coated chassis but its really starting to feel like im building a car, not just assembling meccano

front brakes assembly

Thought I was missing some parts, turns out there are adaptor brackets to use the bigger front brake discs as the caliper sits further out (dia and car width). These are random shaped bits of metal with some holes in that at first I didnt know what they were for so threw them to one side and forgot about them