Tim Broyd Posted October 10, 2005 Share Posted October 10, 2005 I'm currently building a 1.8VVC Roadsport. Build's going pretty well, and I got the engine fired up over the weekend. BUT - I've got a problem with the coolant system. The top hoses and top of the radiator get hot, but all else remains stubbornly cold - as a result the temperature gauge rockets up, the cooling fan doesn't cut in, etc. Can anyone tell me how best to get rid of the air? Thanks Tim B Link to comment Share on other sites More sharing options...
Pelico Posted October 10, 2005 Share Posted October 10, 2005 Tim, a huge amount in the archives on this. Do you have a heater ? The biggest problem appears to be that the heater is above the rad bleed plug. Link to comment Share on other sites More sharing options...
Tim Broyd Posted October 10, 2005 Author Share Posted October 10, 2005 Yes - I have a heater. My attempts to date have led to more coolant (rather than air) being expelled through the rad bleed valve. Interesting point about the heater being above the bleed point. Link to comment Share on other sites More sharing options...
Grubbster Posted October 10, 2005 Share Posted October 10, 2005 Tim, quite a good thread on this here and a bit more here. I believe part of the problem is that you have to wait for the stat to open before you get any circulation and therefore air bubbles out. Roadsport build photo's here Le Mans 2004 photo's here Edited by - Grubbster on 10 Oct 2005 15:48:39 Link to comment Share on other sites More sharing options...
rgrigsby Posted October 10, 2005 Share Posted October 10, 2005 Quite a few people have fitted a "Mick Smith" bleed valve in the hose from the heater to act as a high point to bleed the system. Rob G www.SpeedySeven.com Link to comment Share on other sites More sharing options...
Peter Carmichael Posted October 10, 2005 Share Posted October 10, 2005 Have a look at the description of bleeding in this thread. Fancy R400+ performance on a pre-SVA roadgoing Seven- Click here now it's reduced to UKP14500 but doesn't have the Quaife sequential box Link to comment Share on other sites More sharing options...
Nifty Posted October 10, 2005 Share Posted October 10, 2005 Either put the front axle on a four poster and lift to a ludicrous angle or use an engine crane to same effect. That way the bleed valve is feet above the heater *thumbup* Keep off the straight and narrow 😬 Link to comment Share on other sites More sharing options...
Peter Carmichael Posted October 10, 2005 Share Posted October 10, 2005 Which does not prevent the classic K-series airlock by the thermostat. Do all initial filling on the level. Get the air out of the lower rad pipe. Only then is it worth lifting anything and usually you can get by without. Link to comment Share on other sites More sharing options...
Nifty Posted October 10, 2005 Share Posted October 10, 2005 Sorry Peter, I was referring to bleeding out that last annoying bit that always seems to get left. Keep off the straight and narrow 😬 Link to comment Share on other sites More sharing options...
Peter Carmichael Posted October 10, 2005 Share Posted October 10, 2005 Yes, it does help for that. If you don't have a lift, undo the bolts holding the expansion tank (cap off) and hold it above any bleed point - then coolant/air will flow out rather than air flowing in. Link to comment Share on other sites More sharing options...
Tim Broyd Posted October 10, 2005 Author Share Posted October 10, 2005 Thanks to all who've posted a reply. Due to work commitments I'm very much a 'weekend builder', but you've given me lots of tips to work on. By the way, when I filled the system I had to fill the radiator via the bleed valve - filling the expansion tank merely resulted in the expansion tank overflowing without much coolant getting into the system. Is this normal? Link to comment Share on other sites More sharing options...
Peter Carmichael Posted October 10, 2005 Share Posted October 10, 2005 Follow my link. You have to plan to fill both sides of the thermostat - engine side and rad side. If you fill from the expansion tank... it is a long way round to the engine. If you fill from the expansion tank... you have to get rid of the airlocks from the bottom rad hose/J hose/submarine pipe... by flexing it a lot. You will get lots of glugging and then the rad will fill. This is still a lousy way of getting coolant into the engine though. Link to comment Share on other sites More sharing options...
Englishmaninwales Posted October 10, 2005 Share Posted October 10, 2005 Tim, follow PC's method.....I have never had any problems since adopting his routine. Malcolm Link to comment Share on other sites More sharing options...
conorkaby Posted October 11, 2005 Share Posted October 11, 2005 I recently replaced my K radiator and used this method. Fill through the expansion bottle with the top plug removed from the rad until it is apparently full. Replace plug and expansion bottle cap. Disconnect the upper hose from the heater and fill the tube using a funnel with the heator valve open until fluid spews forth. Quickly reconnect the hose. I did this with the engine running and warm and have not had a problem since. It seemed to work for me. A quick hose down to remove collant from the car and driveway and BYU. Link to comment Share on other sites More sharing options...
Myles Posted October 11, 2005 Share Posted October 11, 2005 O/T Spotted the NTL Radtec donation in LF this month, Conor, thanks! Project Scope-Creep is live... Alcester Racing 7's Equipe - 🙆🏻™ Alcester-Racing-Sevens.com Link to comment Share on other sites More sharing options...
prs Posted October 11, 2005 Share Posted October 11, 2005 I've always drilled a small hole approx 2mmD in the thermostat, this cures the problem of getting an airlock in the J pipe. I then fill the system in the usual way and disconnect the top heater hose and attach an L shaped pipe to this and fill it thus making sure the heater matrix is full. I then reconnect the original pipe (fill this right up) and start the engine and leave it for a couple of minutes. I then loosen the top heater hose and allow any air to escape, in reality there is very little if any. I've used this method on numerous ocassions and have never had any problems with airlocks. Phil S7SVN Link to comment Share on other sites More sharing options...
Tim Broyd Posted October 16, 2005 Author Share Posted October 16, 2005 Many thanks to all who've offered help on this one, but especially to Peter Carmichael. I followed the advice, and you're absolutely right Peter - lots of glugging but a lousy way to have to get the coolant system working. But - I now have the 1.8VVC idling at around 1000rpm and keeping to a temperature of around 85deg. I took it out for a run too - all of 50 yards - but enough to check that at least first, second and reverse gears work OK. All that remains is the front wings and lights and interior trim. We're getting there...... Tim B Link to comment Share on other sites More sharing options...
Phil Bishop Posted October 16, 2005 Share Posted October 16, 2005 Chris Wheeler gave me a tip - fill up the expansion bottle, put mouth over hole and blow like buggery. Lots of impressive gurgles later, the level's gone down and you can repeat the excercise. Remember not to suck. Link to comment Share on other sites More sharing options...
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