Jaggies Dad

To answer Jim’s earlier question: yes, the handbrake is off throughout and yes, during the 20 s wait period there is no braking at any wheel. You may all be right regarding disc temps and I’ll check the linkage and mechanism this morning. I’m hoping BG Developments can give me a definitive diagnosis if I’m safe or not. More anon.

Thanks guys all very helpful but here’s an update. I repeated my bleed procedure this morning and no air visible at any wheel but I still require the 20 sec wait after bleeding any of the front before pedal resistance returns. I wondered if I was opening the nipples too far so this morning I only opened enough to get flow but as no air was visible I am happy air is not the cause. My fluid was still pristine although there were some very small black specks on the bottom of the reservoir so this may indicate a rubber component failure in the MS but I am talking a very small amount - no more that 6 specks which I am guessing are less that 0.1mm in diameter. As I have flushed well over 750 ml of fluid through the whole system it is effectively all new fluid but the particles are trapped at the bottom of the reservoir. So, with pedal feel back to as before I decided to take it for a tentative test drive. All appeared as before so I took her out again undertaking several track day like braking on a quiet back road and again, all feels as before. However, this time I measured my disc temperatures with a laser spot temperature gauge I have and it revealed both front around 45C nearside rear 70C and offside rear 58C. Intuitively this does not seem right as I am sure all cars should have a front brake bias so again this may indicate something amiss on the front brake piston in the MS. I have decided to give Caterham a call in the morning and another brake specialist I have come across on Piston Heads, BG Developments, and see if they also conclude I should replace the MS. I’ll update this with the conclusion for your edification. Many thanks again for taking the time to respond. Best

I built my 420R in 2016 and had no problems bleeding the newly filled brake system at that time although it took repeated bleeds to get the pedal feel right. After my last track day at Knockhill I felt the travel was increasing so I decided to bleed the brakes again and started yesterday. I follow the procedure in the manual nearside rear, offside rear, inboard nipple front nearside, outboard front nipple nearside and repeat offside front. The problem is immediately after bleeding any of the front pistons the pedal goes to the floor and there is no resistance but after leaving it to rest for 20 secs or so resistance returns and we can bleed again. I’m am using the traditional hose under oil with my wife as pedal pusher. We keep bleeding until no bubbles are visible for 3 consecutive bleeds and then move on. However until the pedal achieves resistance immediately following a bleed I’m clear there must still be air lurking around. We have been bleeding for several hours and if you let the brakes “rest” for 20 secs or so after bleeding any of the fronts they feel normal and I have braking whereas if I bleed either rear brake the pedal resistance feels fine immediately. But any bleed from any of the front nipples immediately results in no pedal resistance and no braking at any wheel until it’s “rested” for the 20 secs. I’m due to drive to the Isle of Man on Monday but dare’nt until I understand what is happening. Its as though air is being reintroduced somehow but there are definitely no oil leaks as I have scrutinized every part of the circuits. I am suspecting I have a problem with the master cylinder but even if there was a seal problem I can understand how air could be introduced. Needless to say I am ensuring the oil level in the reservoir never drop anywhere near the min level. Does anyone have any ideas or a cut away drawing of the master cylinder I could study? Thanks in advance.

It looks to me that Caterham are fitting the internally driven Raceline DS system to the current Duratec. Go to raceline.co.uk and look under Duratec-R, Dry Sump systems and its what I've got fitted to my engine.

7 Wonders, there's not a big blue nut on the current Duratec DS but Mucus72 suggested the finger filter is covered by a small dark grey plate tear drop or diamond shaped plate from memory (not near my car to check at the moment) on the LHS at the back of the DS engine pan. I'll send a phot later. By the way from what I can make out we can't externally access the scavenge pump on the current Duratec - my belt only drives the alternator and water pump I believe.

Thanks ECR, let's see what others might offer.

Many thanks to everyone. I clearly have a Pace Easyclean tank from what is described. I spoke with Derek Howell first thing this morning and he confirmed at the factory they put 3L in the engine an 4L in the tank (not the 6L stated in the Build Manual and the Owners Manual!) He advised to add 2L to the tank and crank her over to pump the oil into the tank. I duly did this and the oil did transfer but it was still well down in the tank. My real worry though was I had no oil pressure even though I had done 5x10 sec cranks so that had me worried. Derek advised that it would take around 30sec of cranking for pressure to build up the first time - and he was right, well nearly, it took 25 sec crank to whack the needle round to 3 bar. Now she immediately jumps to 3bar on any subsequent crank ( no firing obviously at this stage). I estimate it will take another 1L to reach just below the baffle, which on my tank is 165mm below the rim of the filler. I'll leave it for now in case there is more oil lurking somewhere that will return to the tank when she runs st idle speed - a few days away yet. So alls well than ends well I think. thsnks again to all but I'd still like to understand exactly what my DS system really comprises if anyone has further info. One other question - how do you drain the sump, as opposed to the tank, as I can see an o buoys drain plug? cheers everyone

Has anyone got a detailed specification/schematic/description of the DS supplied by CC with the Duratech?

Thanks for that important guidance. To recap I currently have added 5L via the cam cover filler cap and none in the tank. To make sure I've got this right I will drain off around 2L from the engine sump drain plug and put this into the DS tank. I still have 1L to achieve the 6L stated by CC in the Owners Manual so should I put that into the tank before running? That would give me 3L in the engine and 3L in the DS tank. Sound good?

That's great ECR but can I also ask what the correct level should be after running engine and for future top ups should I add directly to the tank or continue via the CSK cover filler cap?

Can someone guide me - I'm close to running my 420R dry sump and probably foolishly followed the Build Manual section 15.7 which after the table giving the oil volumes for wet and dry sump says all variants are to be filled via the cam cover filler hole. I have so far put in 5L (so 1L to go) and nothing is showing in the dry sump tank so where is it going. Is the manual the usual load of b*^%#^cks and I should have put it directly into the tank Do I need to drain the engine and start again? Help!!!

Huge thanks from me too Tom Best regards, Derek

Thanks Jonathan for the link and thanks Richd13 for the washer info. My inner skins must be an anomaly but sorted now following drill, burr and Dremel.

I'm at the same stage with my 420R and my problem is the lower radius arm hole is not matched by a large clearance hole on the internal skin panel through which to insert the bolt, I can create a hole no probs but I'm intrigued if anyone else is missing the required hole? It's the the same both sides. The upper holes do align with clearance holes in the inner skin so I have queried Derek and Mark Rider but no answer so far. By the way, how do you add a photo to the text to a post? Thanks

Having just started my 420R kit I am considering film protection and came across this: https://www.amazon.co.uk/gp/aw/d/B00EOLFUC4/ref=pd_aw_sim_sbs_263_1?ie=UTF8&dpID=51Yt8XdWkvL&dpSrc=sims&preST=_AC_UL130_SR130%2C126_&refRID=YW8DHZMSMBSJAZKMYWYF Thanks L7VCT for the UTube link - daunting but I think I'll give it a go with the TIS film available from Amazon.