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25. Second Croft Trip

Needed to get the rear brakes sorted. So changed the disc and pads and made sure the pads could move and all seemed fine.

However after applying the brakes the rear left was locked solid, this was obviously the problem which caused the pads to wear down so quickly. So in a way I was pleased to find what the problem was.

So took the calliper off to investigate what was causing the piston not to release once the pressure is released. Clamped the piston to see if it would retract at all and would not shift at all. As we are not using the handbrake I decided it was best to remove the hand brake adjustment mechanism from inside the piston then there was nothing which could stop the piston retracting. I am assuming I had assembled the mechanism incorrectly when rebuilding them originally, but didn't want to risk having the same problem again.

Reassembled to the car again and tried the brake again and no issues. Decided to do the same to the right hand side as well just as a preventative measure.

At short notice we managed to get a cancellation spot at Croft (Javelin, 16/7/21). So was a good job the brakes we sorted (so I thought). Bought a spare rear disc and some pads just incase we had a problem in the future so that was the only extra thing we took for the track day. It was going to be roasting so the gazebo was going to come in very handy.

Same setup as last time at Croft. I was sat on the chair on top of the trailer watching James doing laps along with the other cars on track and thought days don't get too much better really.

The roof scoop works a treat whilst moving and neither of us were too hot in the car whilst driving which was great. Maybe a different story when wearing a race suit though. However when you weren't moving, couple of times waiting for red flag stoppages it got a little warm, but kept the door open and was bearable.

So couple of issues on the day. First one was a weird/silly one. When the brakes overheated at the last track day the anti-knock springs/clips pretty much melted so lost their shape so just binned them and thought nothing of it. Whilst James went out for the first session he lost brakes on about the 2nd or 3rd lap, managed to bring the car back in without any issue which was lucky. The dreaded rear left again!

Brake fluid all over the wheel, so off the wheel came and the brake pads were missing. Lucky someone found one of the pads and the retaining angle/pin near by so put the piston back in, put a new set of pads in, put the retaining angle back in with the pins. Gave the pads a rattle and sure enough the angle slipped out and pads could then be pulled out. Not sure if this was caused by not having the anti-knock springs or if the retaining angle was too loose? Anyone else have an issue like this.

James came up with a quick fix, turn the angle round to have the longer side against the pads, neither of us could then wiggle the pads loose so thought we'd give it ago. Sure enough no issues for the rest of the day with the pads. But at lunch time a couple new sets of retaining/fitting kits were ordered to fix it properly.

So the rest of the morning went without issue.

A little after lunch I went out for a session and started to hear the same noise as last time, I was sure it was another rear wheel bearing had gone so thought sod it I am going to finish my stint off and then check it. We tend to do about 20 minutes each then come in and swap over, works well for us both and is the sort of time we would be driving in the Trackday Championship so feel it is a good routine to get in to.

So came in, broke the news to James and sure enough rear bearing was knackered. We had bought a spare incase this happened in the future but wasn't expecting it to happen this soon. Pads were absolutely fine so the problem we thought was one issue last time must have been 2 separate issues but couldn't have helped. Getting good practice at changing rear pads and discs so car was back on the ground in no time and James went out for his session.

So another great day but still left us scratching our heads to what was up with the rear bearing. I know they are a weak point but having to change them every couple hours of running certainly isn't right. Bent stub axles? Stub axles worn down? It wasn't the spacer, that was the correct way round and nut torqued to 175Nm. Anyone got any other ideas?

Eitherway, with Donington coming up in a couple weeks time we didn't want to mess around with finding a replacement stub axles and seeing if that worked so splashed out and bought the PureMotorsport rear stub axle kit, uses the Mk3 discs which have a larger bearing. So this should be the end of the rear bearing issue.

So they should be here on Tuesday (20/7/21). So will show fitting them in the next post. Will be interesting to see how far out the alignment is once fitting the new stub axles. Perhaps that will explain why the Toe was so far out.

James managed a 1:42.247 and I managed a 1:43.284. I was happy that I managed to close the gap a little bit compared to last time and after a quick look at the lap time data I was losing 0.9 seconds in one braking point and corner so not too far off at least. I will do a proper post on the ECUMaster lap timing software when I have a proper look at it and get some decent onboards to link the times too. However this is the sort of detail it gives you. Can break the lap down by every straight and corner to compare laps.

Will be even better once ECUMaster release their new bit of software which allows you to add video to the analysis software, will be really cool. And will be great once we become more consistent and start dialling in the setup.

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