diggerman

A modern master cylinder should last 15 years, specially if re-sealed as you've done, but corrosion is the killer.

The only way to see what's going on is to take it to bits and all should then become clear.

Peter

Sounds to me like a piston is seizing, a return spring broken and/or a seal has been damaged. Sorry to say this but if I'm right you should replace the whole unit.

I am assuming that the master cylinder is quite old, and perhaps the brake fluid has not been regularly changed? This being the case it may not only be worn, but also corroded internally. Harsh comment but this may be a serious safety issue.

Peter

12,000 miles in total and 9000 miles with BMW diff fitted by Catmids. No loose bolts, cracked carrier as far as can see, or marks on dtube. I will keep a close eye though. Car is 2010 Roadsport 150SV with non adjustable shocks, no watts link and no LSD.

Most of the miles have been done on 14in wheels but have just changed to 13in.

Peter

I've just fitted 8in 205 x R13 rear and 185 x R13 front to my Roadsport 150 SV. Tyres are yoko 044. I wondered whether it my be inclined to under steer but in fact the handling is really good and the car looks great!

Peter

Yes, but it will leak again so call them and negotiate a special price to upgrade to an aluminium rad. It will cost a few pounds but resolves te problem forever.

That's what I did after two failures of the plastic rad!

Peter

My immobiliser failed as you describe during the summer. Trailered to Dartford for a replacement unit. Caterham told me that only approved companies can fit and that wires are not colour coded so that amateur fitting is virtually impossible.

Peter

Are your wheels 13 or 14 inch. If 13 I may be interested in the case that you by new wheels.

Peter

Looking for 13inch wheels, 2x8 and 2x6 for an SV Roadsport. Must be undamaged and preferably silver but any colour considered.

Peter

Also try some more bleeding. It only takes one tiny bubble to severely reduce the slave cylinder travel.

Peter

You must fit a thermostat!

No, you really MUST fit a thermostat ...... Otherwise it will run cold!

Peter

Platinum and even more so Iridium plugs will perform better than bog standard plugs in circumstances where cylinder and turbo/supercharger pressures are very high and the spark is no longer reliably igniting the mixture. They do this by utilising small diameter electrodes which for the same ignition voltage produce a more intense spark. Standard electrode materials would not last if produced at this small diameter.

A naturally aspirated Sigma is not running such high pressures so I very much doubt that a performance advantage would be available. It woud be interesting to hear from some of the big boys with 200hp + engines. Is there any evidence that more exotic plugs produce performance benefit?

Peter

This might make the NGK site easier to find.

here

Peter

The standard factory fitted plug is NGR BPR5ES.

Take a look at this site for a helpful explanation of the specification http://www.sparkplugs.co.uk/pages/manufacturer/about-ngk-spark-plugs.htm

Peter

Mark,

This is totally normal. I have a Sigma 150 now 10000 miles old and it produces at least as much gunk in its catch tank.

The contents of the catch tank are nothing to do with piston leakage or similar sinister goings on. It is a mixture of condensation from engine warming and cooling and oil mist from moving parts. In past times these substances were simply vented to the atmosphere, but in these environmentally cleaner times we are required to catch them.

Makes you wonder what most do with the catch tank contents, down the drain?

Peter

Totally happy with mine!

You might find that the backlash in the Sierra diff is what makes the throttle seem harsh. With my first diff I had to slip the clutch to go from over run to power. That's no longer necessary with the BMW diff.

Peter

As Jonathan said, there's load of info on this subject, but I can tell you I did it and it's a perfect and total solution.

Peter

Michael, welcome to blatchat.

I have a Roadsport Sigma 150 SV that I built from a kit 2 years ago. It's a fantastic rapid reliable comfortable car that has transported me and er across Europe and all over the uk. 10000 miles plus completed. I spent a lot of time making sure the car was well screwed together as I am a bit obsessive compulsive about squeekes rattles and knocks. I also changed the diff to the current spec BMW version as I could not live with the Sierra unit that is so noisy. I got Caterham to install the latest MAP which makes the car much easier to drive and changed the rubbish plastic tanked radiator to an all ali job. Am now I'm happy

Now to be highly controversial, may I dare to recommend that you go for a Sigma engined car. K series engines seem to have all sorts of issues. The Ford unit seems to be bomb proof.

Head down

Peter

I will now go into hiding before other blatchat members read this.

When I built my Sigma 150 it needed about 4 litres before it would start, so guess that much of the tank is un-useable. If I run it to the bottom of the red section it will take about 28litres to the brim. So the safety margin is about 10 litres which is perhaps not unreasonable. I therefore drive with confidence to the bottom of the guage.

Never run out so far.

Peter

Have started the bidding for your 14in yoko,s

Peter

Ok ok if I have to compete with a 205GT bloody i , anyone interested in this very clean Astra at £899.

Peter

My daughter has aquired a company car and her Astra is now surplus. It's been serviced by the local garage and apart from a nearside front corner scrape is nice and tidy. It has recent tyres and MOT and only 77000 miles. It's a silver 5 door 1.6 Club version. Could be an ideal first car or a run around for a 7 family? Price £990.

Peter

Thanks everyone 021's it is then

Peter

My Roadsport 150 SV is now in its third year (10,000 miles) and the standard Avon ZV3 tyres still look like new. They really refuse to wear, and don't grip much either!

Everyone says that better tyres transform the car, so am looking for recommendations. I want to continue using the 14in wheels and have tyres for wet and dry rapid road use. What do POBC recommend?

PeterC