Chris's new build of an MX5 based car

[Davidbolam]

Originally Posted by CTWV50

This weekend I spent the time I had with the car out the garage sorting out the rear wheel geometry, then replacing all the nuts with nylock nuts. I also discovered a problem with both rear callipers. Both weren't allowing the piston to return to the fully retracted position after disengaging the handbrake. One of these callipers I had refurbed but the handbrake pin was really stiff so I replaced the calliper with a good used one I had from the 1.8 mx5 I stripped. This one was worse as there just wasn't enough adjustment or space for the new pads and discs.

So I removed this one and made some space with a metal file. The other one on the right side appeared to have a weak return spring. I dug out a better one from my brake spares box and that one now works ok. After a bit of research I discovered all the rear callipers I have had (four) are all chinese copies. If I experience any more issues I might just have to buy some genuine mazda ones. I hope I don't have to.

I also got the dash screwed in place, I'm just waiting for some new hazard/fog switches and some perspex to turn up and then I can wrap it and do the rubber edge trim.

Re reading the IVA manual I can't be sure my upper harness mounts will pass, as once again the manual is ambiguous and fails to specify what is considered "thick" walled tube. My 7/16 UNF upper harness mount nuts are welded inside a length of 2mm walled 25x25mm box which is fully welded onto the top of the rear backrest top rail. I may order some unf bushes and weld them to the side of a piece of 40x40x3mm SHS and make a harness bar and bolt it into place instead of the roll bar I have made.

The handbrake on the mx5 has a bolt on the side (about 14mm) which you need to remove and then use a 4mm allen key to retract/adjust the piston when you replace the pads etc.

I bought a new set as I thought my old ones were bust but then i worked out how to adjust them

David