Page 2 of 4
Re: Missing expansion tank?
Posted: 27 Jun 2021, 11:02
by Oldiebut goodie
GATES 6215MC V-Belt Length: 875mm, Width: 10mm for FORD, Volkswagen, MERCEDES-BENZ, BMW, AUDI ... GATES Spares: V-Belt Art. Nr: 6215MC for car.
Who knows why someone put that on!
yes, holes are for tank.
Re: Missing expansion tank?
Posted: 27 Jun 2021, 11:09
by Bryce
Oldiebut goodie wrote: ↑27 Jun 2021, 11:02
GATES 6215MC V-Belt Length: 875mm, Width: 10mm for FORD, Volkswagen, MERCEDES-BENZ, BMW, AUDI ...
GATES Spares: V-Belt Art. Nr:
6215MC for car.
Who knows why someone put that on!
yes, holes are for tank.
So I'm guessing it's definitely the wrong belt then? Had two the same as spares in the van when I bought it as well.
So my plan is to take the belt off, set the alternator to half way up the tension bracket and measure with string and go from there. Please somone stop me if I'm about to make a colossal c**k up
Re: Missing expansion tank?
Posted: 27 Jun 2021, 12:41
by Bryce
Measurement came in at 810 and Closest I can find is a 838 which although bigger should be short enough to get correct tension (I hope). I have used the calculator provided above but I can't be sure of the stretch factor as the seller doesn't list what it is made from.
On the missing expansion tank, is it essential to have one or can I put it off to do over winter? I would love to actually get out in the van before the frost sets in

Re: Missing expansion tank?
Posted: 27 Jun 2021, 13:09
by muttleypup
looking at pics it appears the alternator pulley doesnt line up with the others and the belt runs at an angle, might be a trick of the eye though?
if it is misaligned maybe the long belt was used for more flex. the two spares in the van might point to an issue with premature belt wear. the alternator looks 'new' so maybe has wrong pulley fitted, theres a note on Brickwerks as follows:This alternator is not a straight fit. The bore for the swivel that the alternator mounts on should be 8mm but on these aftermarket alternators it's 10mm.
If you bolt it on unmodified it won't sit straight and will probably keep throwing belts off, you will need to sleeve this area for it to fit and work as it should.
Furthermore they are fitted with the wrong pulley so again modification is required by fitting the old pulley from your old alternator or buy along with the one listed below in related items.
Re: Missing expansion tank?
Posted: 27 Jun 2021, 13:29
by Bryce
Oh dear looks like you could be right. Wonder if it's all related and If it threw a belt which broke expansion tank so they just took it out.
All I wanted to do was top up the bloody coolant!
Re: Missing expansion tank?
Posted: 27 Jun 2021, 13:37
by Bryce
Looking again they do seem to line up ok

Guess I will find out when I fit the new size belt tomorrow
Re: Missing expansion tank?
Posted: 27 Jun 2021, 13:57
by muttleypup
does look ok in that pic. only other reason for long belt being on there is sheer laziness as it avoids the need to take off the water pump belt/splitting the two part pump pulley when fitting new alternator belt
Re: Missing expansion tank?
Posted: 27 Jun 2021, 16:34
by Cecil
Looking at the photos and the various pulley diameters the long belt is trying to turn the water pump relatively slowly whereas the short belt is trying to turn the water pump relatively fast ,the result will be lots of screeching as the 2 fight against each other.
I believe that originally the alternator belt would only go around the alternator pulley and the water pump pulley leaving an unused groove on the crankshaft pulley.
The differing sizes of pulley groove diameter on the water pump pulley will run the alternator and the water pump at the rpm intended by vw . Changing the belt arrangement from what vw intended will possibly mean the water pump and the alternator will under perform.
Yes those 2 holes are to secure the coolant tank . Easy and fairly cheep job to re instate!
worth getting a new good quality darlek cap (Blau or genuine vw) to give you the best chance of the coolant to stay where it should.
Re: Missing expansion tank?
Posted: 27 Jun 2021, 17:25
by Bryce
Cecil wrote: ↑27 Jun 2021, 16:34
Looking at the photos and the various pulley diameters the long belt is trying to turn the water pump relatively slowly whereas the short belt is trying to turn the water pump relatively fast ,the result will be lots of screeching as the 2 fight against each other.
I believe that originally the alternator belt would only go around the alternator pulley and the water pump pulley leaving an unused groove on the crankshaft pulley.
The differing sizes of pulley groove diameter on the water pump pulley will run the alternator and the water pump at the rpm intended by vw . Changing the belt arrangement from what vw intended will possibly mean the water pump and the alternator will under perform.
Yes those 2 holes are to secure the coolant tank . Easy and fairly cheep job to re instate!
worth getting a new good quality darlek cap (Blau or genuine vw) to give you the best chance of the coolant to stay where it should.
Thanks, I already bought the blau cap to replace the oem black one but it turns out the plastic thread on the tank itself has stripped so will need to replace that as well
So with having the two belt setup will I just have to live with a screaming alternator belt as can't see another way of routing them. I'm hoping for miracle when I change it for shorter belt tomorrow as the noise completely stopped at lower revs when I tightened it to highest point today.
To think I talked the wife out of buying a mazda bongo for the t25

Re: Missing expansion tank?
Posted: 27 Jun 2021, 19:05
by Cecil
Cecil wrote: ↑27 Jun 2021, 10:38
This is what the arrangement should be. The long belt over 3 pulleys not required .
Re: Missing expansion tank?
Posted: 27 Jun 2021, 19:15
by Oldiebut goodie
You have measured round the middle pulley and the alternator pulley haven't you? The belt is around 600 if my memory serves me well. The above reads as though you are going to put the belt on the bottom pulley again which is incorrect.
Re: Missing expansion tank?
Posted: 27 Jun 2021, 20:06
by Bryce
Oldiebut goodie wrote: ↑27 Jun 2021, 19:15
You have measured round the middle pulley and the alternator pulley haven't you? The belt is around 600 if my memory serves me well. The above reads as though you are going to put the belt on the bottom pulley again which is incorrect.
I had measured where the belt ran that was already there. So originally it would of ran from alternator to middle pulley? Would this not still produce noise from the two belts being on the same pulley?
So should the first slot on the bottom pulley remain empty? Sorry for all the questions I'm just trying to get my head round why it was set up that way in the first place! Brickwerks shows it should be a 600 x 10 belt
Re: Missing expansion tank?
Posted: 27 Jun 2021, 20:15
by Oldiebut goodie
The long belt is on the wrong pulley - it runs around the top two NOT the bottom crankshaft one.
Re: Missing expansion tank?
Posted: 27 Jun 2021, 20:19
by Oldiebut goodie
Cecil wrote: ↑26 Jun 2021, 23:39
Cecil's diagram post earlier and photo shews the correct set-up.
Re: Missing expansion tank?
Posted: 27 Jun 2021, 20:30
by Bryce
Cheers. I will buy the 600 and fit it like picture and see how we go
Any idea why the bottom pulley would have two spaces for belts? I just don't want to catastrophically destroy something by changing how the previous owner had it set up