The Triumph Dolomite Club - Discussion Forum

Karlos wrote:Any further ideas as to why the needle never gets above 1/4-1/3 on the gauge are of course welcome.

Not really ,
I started a thread on this very subject but didn't get a definitive answer, however I can make an observation....

With an 82 degree thermostat, both the Sprint I had and 1850 I currently run ran at halfway during the summer but only 1/4-1/3 during winter,
whereas with an 88 degree thermostat the 1850 runs at halfway irrespective of the season or weather.
An 88 thermostat is the original spec for an 1850 but Sprints came with 82 degree ones (so I suspect also did the 1850HL?).



Ian.

GTS290N wrote:Radiator cap here:
http://www.ebay.co.uk/itm/Polished-Stai ... OC:GB:3160

Yep I did look at these but it says it is only a short reach cap 20mm long between seals, this one is from the same manufacturer but states it is only 22mm depth (so again probably 20mm between seals) and it is a 5'er cheaper:
http://www.ebay.co.uk/itm/Fahler-Polish ... 1880862008

However I doubt either will be any good as they are too short.

Hi Karl,

The cap in my original link works perfectly on my 1850, I took some rough measurements.
Plastic sealing lip inside tank to top of metal sealing ring on neck of tank: 20mm (roughly).
bottom of rubber foot seal to bottom of neck seal on cap: 21mm (roughly).

This definitely seals, I checked it several times after it was fitted.
But here's the photo that gives the proof it works on my car, you can see the rusty ring from the neck of the expansion tank and the indentation where it seals against the lip inside the tank:
rad cap

GTS290N wrote:Hi Karl,
This definitely seals, I checked it several times after it was fitted.
But here's the photo that gives the proof it works on my car, you can see the rusty ring from the neck of the expansion tank and the indentation where it seals against the lip inside the tank:
rad cap

Can't argue with that, yours definitely seals!

Curiously today I brimmed the tank, and notice the fuel gauge only read 3/4 full.

Just measured the depth of the neck of the expansion tank, I get approx 21-22mm - thought I may as well find out what i actually have. Measured the length of the cap, from cap seal to the sprung seal - 19mm. Will have to buy a proper cap!

Karlos wrote:..............

Curiously today I brimmed the tank, and notice the fuel gauge only read 3/4 full.

Perhaps your voltage regulator is dodgy, it should give out 10V and feeds only - the temp and fuel gauges. £1.09 for a 10v regulator from Maplin:
http://www.maplin.co.uk/p/ts7810cz-1a-p ... case-n38ca

Ian you say 88 is the spec for early 1850's which would of course have had metal expansion tanks.
Wonder of that has anything to do with it?

The plastic ones are crap. My P6 V8 also has one added as an expansion tank. Needless too say it vents coolant, so I have done away
with it as an expansion tank and gone back to just having the sprung cap in the rad as per OE. It no longer vents coolant but Ive kept
it as an overflow catcher.

Jonners

RC3 - Safety - Show Radiator Cap
Same as RC1 with safety valve to release pressure
Diameter 60mm
(inner washer to bottom washer) 25mm
Select Pressure, then click button to purchase:

£11.95

RC1 - Show Radiator Cap
Diameter 60mm
Standard Short Reach
(inner washer to bottom washer) 25mm
Select Pressure, then click button to purchase:

£8.95

According to their website, the above caps are for Dolomites.

Maybe they read this post and decided to make their price a bit more competitive by lopping off 50%.

Karlos wrote:Maybe they read this post and decided to make their price a bit more competitive by lopping off 50%.

The power of the forum!

Ordered an RC3 £7.45

I'm tempted myself...

Jon Tilson wrote:Ian you say 88 is the spec for early 1850's which would of course have had metal expansion tanks.
Wonder of that has anything to do with it?

I doubt it, given that the early Sprints came with the same expansion tank.





Ian.

So.... an update eventually.

New rad cap made no difference. I bought an 88-deg thermostat last month and an ex-MGB watertemp/oil pressure gauge, got it for £45 which I though was a bargain, just needed a T-piece and pipe which I got for £12.50, so still a good price. I fitted the gauge first and check the temp - same kind of reading about 1/4 - 1/3 along the scale. Swapped out the 82 thermostat for the 88, checked again, temp gauge showed just under 1/2 way - going by 90-deg being halfway I'd say it was reading the equivalent of 88. The definitely warms up more quickly and seems to run a bit better at the slightly warmer temp. Heater is much warmer too - nice.

Thing is though the cooling system doesn't seem to pressurise, I'm not loosing coolant externally or internally, the level has not changed as far as I can tell. So where is the pressure going?

I bought a stainless filler neck the other day too, to fabricate a stainless expansion tank that I can mount higher than the current plastic one. Probably hang it from the 3 nuts on top of the suspension top mounts/turrets.

Had some fueling problems recently, fuel was initially leaking from pipes between the fuel pump and the carbs so I replaced those.



Then I still had problems, my inline fuel filters kept draining and showed small bubbles being drawn through when the engine was running. All due to corroded and perished fuel lines:



Made a replacement pipe for the part that goes under the floor of the car between the axle and engine bay and fitted it.