SimonR300

I had a lot of trouble bleeding my brakes after replacing the two rear brake lines. I have this M/S https://caterhamparts.co.uk/master-cylinder/29-master-cylinder-apracing.html and race spec AP calipers. I too pumped litres of fluid through while trying fancy valved bleed nipples and all sorts. In the end, I reverted back to a set of new standard nipples from CC. No more air coming through but I still had a very soft long pedal. So I replaced the seals in the M/S https://caterhamparts.co.uk/master-cylinder/1817-seal-kit-1316q-ap-master-cylinder.html and removed the rear calipers so they could be tipped up. They are mounted horizontally and trapped some air. The old bleed nipples had been installed by DPR Motorsport with PTFE tape which is a no-no for me in case some ends up back inside the caliper piston. There was also O-rings on some of them, so clearly they had trouble with air leaking in past the threads. The m/s seal kit (CP4627) came with an exploded diagram and details of the slight differences between the main 4 seals. I was so desperate that I also bought a new M/S in case changing the seals didn't work as time was running out before an event. Then after that event, I bled the brakes again and got a bit more air out. Nightmare job. One of the hazards of buying an ex-race team car that has had lots of work done on it and some of the threads (ie caliper) used more than a road going car. I did get on well with the Eezibleed kit, but you still can't beat the foot on pedal method if done correctly. I should just add that once I had solved the various issues with air in the system, I also had an inconsistent pedal and it was changing the seals that was the final fix. I certainly had a fine layer of black coating the bottom of the reservoir which I couldn't thoroughly clean out so I got a new reservoir to go with the new seals as the reservoir cap thread was leaking too.

Hi Paul and everyone else, I'm no expert and not wishing to give advice to someone else about a subject of which they are already familiar (and probably more so than the first person)......but in the interest of safety and sharing my experience.... When you said "done up nice and tight", it got me thinking. I described using shake-proof washers and threadlock to stop the M8 hex head bolts coming undone, especially because if they did, they could drop out onto the road, but mainly because I didn't do the bolts into the rivnuts nice and tight. (Or the bolts into the seat because that has bonded threaded inserts too.) Rightly or wrongly, I used aluminium flat head round body splined rivnuts and tightening a steel M8 bolt into one obviously needs caution as it it easy to rotate the rivnut, deform it or strip the thread. Being a race car, I will be taking the seats in and out quite a bit too, so the prospect of a rivnut coming loose inside the box section doesn't bear thinking about. I've used steel rivnuts a couple of times but they were small, M4 I think, and very hard to set with a hand tool. So using aluminium M8 rivnuts set into the 35 x 35 x 2 mm aluminium box section seemed physically possible without buying a pneumatic setting tool. I don't know if Caterham use steel rivnuts but clearly they are preferable. It is the seat belts/harness that holds you into the chassis in the event of a crash and not the seat. However you don't want the seat coming adrift in a crash either. So anyway, I've done a bit more googling and found a couple of rivnut manufacturer's data sheets. If I understand them correctly, it is as I thought, you can't do an M8 bolt up to the usual 20-25Nm or more. I didn't use a torque wrench on mine and just went with feel. The highest torque setting I've seen for aluminium is 23.5Nm but these two data sheet are similar, 17-18Nm, which isn't very much. These figures below are for the various aluminium rivnuts from their range... Another way to use box section without rivnuts would be to cut an acute angle at each end, so you can drop a bolt down through the floor and put the nut on the underside. If that came undone, the bolt might stay in place until you turn the car upside-down, but you'd need a very long extension on the ratchet to reach down behind the seat to the cap head and another person hanging onto the nut. You could probably get to the front ones ok. The bottom line is to use Caterham supplied box section and use an appropriate torque value for the rivnut material used! Edit*** Turns out I used Stainless Steel M8 rivnuts. Still don't want to mess up any rivnut thread or find them turning .

Glad it helped a bit and hopefully will give some guidance to others in the future. Just out of interest, were the box sections supplied with rivnuts and bolted down from under the floor as I did? The adjustment slots are certainly an improvement to the above.

Just to add to ECR's advice; My car came with a bad leak from the cap, so bad that the ECU below the master cylinder was sitting in a puddle which had burnt the paint across the deck. I tried new caps with a fresh rubber seal but it still leaked. Then I realised that the bellows was full of fluid which could obviously escape through the breather/pin hole in the cap. So I bought a few new bellows, only to find that they also where not air tight. As I understand it, the bellows should create a dry air seal/chamber between the breather hole and the fluid so as the fluid level goes up and down, the bellows can go up and down, drawing air in and out of the cap. The bellows therefore stop moisture rich air being hydroscopically drawn into the brake fluid. The bellows should be fitted to the cap first or there is a chance that the cap will not make the correct seal with the bellows and rim of the reservoir. It also should be compressed if you can or it will displace quite a bit of fluid and not function correctly. Standard race car practice seems to be to add a piece of paper towel/cloth over the cap with a cable tie to absorb any other leaks. I also found that previous race mechanics had over-tightened the cap in desperation and damaged the thread on the reservoir, so there was a leak from the cap thread as well. Although difficult to obtain, I fitted a new reservoir and finally have a leak free set-up.

I have an S3 R300 race car which came with a driver's lowered floor, Caterham adjustable runner and Caterham composite seat. I had to renew both the runners and seat, fit a passenger lowered floor and seat. Presumably with the SV, you'll have a bit more room, but mine was tight. The Caterham runners have just the one lever which extends under the cross member in the floor and through the cutout in the vertical plate between the chassis and floor as you've said, so I'm not sure how you'll get on with the TR1 runners. Maybe you can't use them with the lowered floor? I noted here the problems everyone has bolting in Tillet seats from above, so I elected to fit M8 rivnuts to the underside of my runners and bolted them in from below with suitable washers and threadlock. I keep an eye on them. Replacing what was there with new runners and a B6 seat was fairly straight forward. The new lowered passenger floor had to be drilled for the seat bolts. I used a Tillet W1i and made up my own aluminium box sections as I couldn't get hold of the Caterham one's at the time. First you bolt the box section to the seat with suitable spacers to angle the seat back as required and to clear the bulge on the seat bottom, drilling though both sides of the box section, opening up the one hole for the cap head. Again I used shakeproof washers and threadlock for the final fit. Then I bolted the box section onto the floor, again from below, into M8 rivnuts fitted into the box section. This is what Caterham do I think. Just make sure the box section is heavy duty enough and the rivnuts are perfectly fitted. The slightly tricky thing is working out where to drill the holes. Various cardboard templates and head scratching required. The Tillet seat fixings are the same spacing as the Caterham composite seat, so you might not need to move the holes around in the Caterham box section. The Caterham runners have holes that align with the Tillet seats. Tillet could tell you if the XL seat has the same spacings to the fixings as the narrower B6 seat I fitted. I found this photo ( http://www.caterhamr500.co.uk/ ) which helped me. It shows the the standard Caterham runners and box sections with the opened up holes to access the cap heads into the seat an the rivnuts in the box section. My previous runners (worn out ) had bolts welded in place so nuts could be fitted from the underside of the floor. Good luck.

I expect you know about this material which expands when heated. There is a calculator to work out how much to buy. I can recommend it. http://www.textiletechnologies.co.uk/acousta-filr-zt1-exhaust-silencer-packing.html Here is the McMillan racing additional silencer. Stumbled across it the other day. Posted on 3rd May. https://en-gb.facebook.com/McMillan-Motorsport-221277681273020/

Might be out of stock but should give you some ideas. https://caterhamparts.co.uk/nose-cones/1936-timing-strut-fits-to-nosecone.html Here are the MSA dimensions; 10.9. Timing Struts – Where timing is activated by a light beam, the vehicles will be fitted at the front with a vertical timing strut, minimum vertical height 254mm, the bottom of which shall be not less than 180mm and no more than 200mm from the ground. The strut will be in matt black on both sides, over its total area, which shall be not less than 254mm by 51mm. No other, or further forward, part of the vehicle may interrupt these dimensions or actuate the timing.

Many thanks chaps. Will look forward to hanging onto your coat tails at the odd event, with my tonneau fitted. Simon

Thanks Mike, I had the same thought as aluminium is not exactly rigid. You would think that running the car with the standard race tonneau with the FIA Approved Roll Cage padding should be ok. Certainly it was original spec for the car. I need it to comply with Modified Specialist Production and not be pushed into Sports Libre to comply with the Non-Race Nat B licence my sons currently have. Thanks Philip, good to know you haven't been challenged.

I've sent in an entry for the June meeting at Gurston Down in my recently acquired R300. I notice the Blue Book states only soft tonneau covers are permitted. I spotted a couple of aluminium tonneau covers in photos at the recent Goodwood Sprint I think. I was hoping to run my car with an aluminium tonneau, as it was run in the Superlight R300 Championship races in its previous life. I would be grateful for some guidance.

If you just need to fill the holes, rather than put bolts through them, what about blanking (or blind) grommets. Search Caterham Parts or ebay etc for various sizes. Try https://www.grommets.co.uk/products/grommets/blind-rubber-grommets/ for measuring advice and stock.