Polo rad. UJs and Brakes (July-August 2006)

Given how hot it was in July I was worried how my cooling system would cope at Silverstone. I've never actually taken it on track in hot conditions: just warm, and even then it runs at around the 100 degree mark. 100 degrees is not terrible, but on a hot day it might rise considerably higher, and that would be a worry. So I decided to change the old Escort rad for a nice lightweight ally one (from a Polo). I ordered the upper brackets from Westfield, some samco hoses from Rally Design and got the rad locally. I had to grind off the old upper radiator mounts, as they got in the way of the inlet pipe. I also made some bracket extensions for the lower fixings, as the existing ones were a bit short and too far apart.

I decided to reuse the old fan. This was mounted on ally bars that could be bent to shape and riveted to the chassis using P clips. This wasn't a hard job, but took quite a bit of time to get it as close as I wanted to the radiator. Some of the hose elbows I bought were the wrong angle (that'll teach me to guess what I need) so I had to order a couple of replacements, but the hosework was pretty straightforward. I decided to take it diagonally across from the water pump to the lower radiator outlet, rather than use 90 degree bends, as I thought that might help the flow of coolant, though it probably makes very little difference. I left the original pipework from the right hand side of the engine, as this did not need to be changed. But I will change that at some later date so that it is all new (and blue!). I also plan to add a swirl pot by the thermostat to replace the header tank, as this would be a more economical system and would enable me to top up without taking the nose off the car. But that'll have to wait till the bank account recovers.

UJs and brakes

I replaced one of the rear UJs earlier in the year. I should have replaced them all then, but didn't. So while the car was off the road I thought I'd replace the other three. But I didn't fancy spending ages tapping out the old UJs so once I got the drive shafts off, and removed the uprights and drums, I took them round to my local mechanic and paid for him to change them over. When I got them back I put it all back on the car, reconnected the brake pipes and prepared to breed the brakes.

I attached my little bleeding kit to one of the rear nipples, topped up the brake reservoir, and was about to set about bleeding them when I realised that the bottle I was holding in my hands was not brake fluid but the bottle of oil that was stored next to the brake fluid bottle. I immediately siphoned out the oil from the reservoir, topped it up with brake fluid, siphoned that out, but there was still an oily scum on the top of the fluid. I decided that the best thing to do was to bleed this out of the system. I later was told that this was the worst thing to do, as the oil causes the seals on the master cylinder and brakes to expand and fail. What I should have done was just remove the reservoir, clean it out and replace it. The Silverstone track  day was now less than a week away, and I really didn't want to have to worry about my brakes whilst on track, so I decided to replace everything. I bought a new master cylinder (from a 1980 Mk IV, 1600 Cortina Estate), and new M16 callipers. I already had a new drum slave cylinder, so I only needed to buy one for the rear.

The new slave cylinder did not come with a pushrod connecting it to the brake pedal, so I had to remove the one from the old master cylinder. The pushrod had a ball end that was held in to the cylinder by a convex washer and a plastic circlip. Unfortunately the plastic circlip was too thick to slip into the groove in the new cylinder, and the metal circlip that came with it wasn't wide enough to hold the washer in. So I had to cut the washer off and replace it with a bigger one. I assumed that the old washer had become convex through use, but as I later discovered it was deigned to be that way. The flat washer I put in would cause me three days grief.

Once the master cylinder was fitted and the reservoir thoroughly cleaned out, I flushed the system though again with clean brake fluid, and then fitted the other new brake parts. Changing the front callipers was a pretty quick and painless job. The offside rear slave cylinder was also a quick job. But I had real difficulties changing the nearside cylinder as the bolts holding it were sandwiched between the back plate and the upright, and I couldn't turn them. So I had to remove the back plate, which seemed to take ages.

I bleed the brakes, cleaned up and took it out for a test drive doing a lot of heavy braking. Things started off well, but after about five minutes of this I could smell burning brake pads, and this got worse. I also noticed that the brakes were binding and that this was getting worse and worse. I managed to get it home with smoke pouring off the front pads and completely seized. Not good.

After a telephone call with a friend I thought that perhaps there wasn't enough pedal travel, so I spaced the master cylinder out from the pedal by about 5mm; took it out for another test drive, but the problem persisted. So I phoned up my local mechanic. He also thought that there wasn't enough pedal clearance. I knew it couldn't be that, but it made me think back to that convex washer. The flat one I replaced it with would hold the ball end of the pushrod into the master cylinder an extra 3mm or so. That would have the same effect as though the brake was slightly on all the time and might be the cause of the problem. So I took the cylinder off and set about trying to modify an ordinary washer to get the right shape. I also ground off some of the ball of the fork to help with the problem. After three attempts with a hammer and a dremel I got a washer the right shape, and set about putting it all back together. This was really the last chance for my track day as it was now the evening before Silverstone. So once again, I bled the brakes, cleaned up and took it for another hard braking test drive; and too my delight it worked. So the track day I had been looking forward to for a number of months was saved. What a relief! I will NEVER make the mistake of putting oil into the brake system again. But at least I had all new braking components, so I needn't worry about the brakes, and the new master cylinder and parts did improve the feel of the pedal.