HP Pump belt tension

Wooscary · Post by **Wooscary** » Tue Nov 23, 2010 1:28 pm

This should be really tight right?

Mine seems a bit loose. No symptoms that I'm aware of.

So, how do I (if I need to) tension it?

Cheers

Martin
(Who is driving to Berlin at the end of December and is starting to worry about things a lot more) So I'll probably be asking loads of questions.

Mothman · Post by **Mothman** » Tue Nov 23, 2010 4:54 pm

Hi Martin,

it should be really tight, did mine with a mate on Sunday. Just loosened off the nuts n bolts holding it in situ [2 from memory] and leant against it with a pry bar whilst redoing the nuts.
Mine was squealing a lot of the time, very annoying but all sorted now.

Andy

Wooscary · Post by **Wooscary** » Thu Nov 25, 2010 3:35 pm

Cheers. Yeah, there's definitely slack in mine.

I think I need to find a photo of the area with arrows, as I can't really visualise the nuts and bolts of which you speak.

tim · Post by **tim** » Thu Nov 25, 2010 5:22 pm

It's dead easy. Think alternators - one main through bolt to lock it up plus a slotted arm to stiffen/brace it up with smaller locking bolts on each end of this. Look down just underneath the pump and you'll see the thread of the bolt on the rh side (as you are looking down) with a nut on it. The bolt has a locking flat on the other side so you don't need to hold it, just slacken off the nut with the appropriate spanner. Just above the pump you can clearly see the slotted arm running forward to the engine block and the locknut holding it in place (11mm from memory but that's the one ring size I don't have so have been using a 7/16 AF instead.) Slacken locknut, insert crowbar,
lever scientifically until belt is tighter than a choirboys bum in a seminary, then retighten. Obviously if you are taking up more than a certain amount of slack then the arm will have to move which means slackening off the locking bolt at the engine end, but that is your call. Personally I like all my nuts and bolts to work which means undoing them whenever you have an excuse to.
You may recall my post a few weeks ago about the warning light coming on intermittently and I got much useful advice. But none of it hit the bullseye - the problem was due entirely to a stuffed belt slipping on the pulleys (you couldn't see it happen, but it was doing it anyway.) The thing was a wreck, several teeth missing and well polished. One new belt later, tightened as per forum advice, problem solved. I had a look at the junker spare we keep on the farm and it was just as bad, and the condition is VERY difficult to see without removing and handling said belt. So if you are in there remove it completely and inspect it in a good light. At less than a fiver (unless you are being ripped off) changing it has to be a good thing, if there is any doubt.

Brian · Post by **Brian** » Thu Nov 25, 2010 8:06 pm

Very good advice from Tim /\.

But:
If after you have finished the tightening process, and the belt still not ultra tight.

Then look at the end of the slot in the flat metal arm, if may be at the end of the provided adjustment.
If so a new belt will be required.

But as an interim measure, elongate the slot with a round file to allow further adjustment.

Good luck

Wooscary · Post by **Wooscary** » Fri Nov 26, 2010 9:45 am

Excellent. Cheers for all that, should be much easier to visualise now.

I've got a new belt knocking around anyway, and although I'm pretty confident the one that's on there is new in the last year, I'll probably whip it off, as it isn't exactly a horrible loopy routing (unlike the aux belt on Passats...shuddering just thinking about that).

Anyway, cheers again.

Next up the weird noise on acceleration....more on that later.

KevR · Post by **KevR** » Fri Nov 26, 2010 10:25 am

tim wrote: (11mm from memory but that's the one ring size I don't have so have been using a 7/16 AF instead.)

Shame on you - sign of a proper Citroënist is to have a selection of 11mm spaners for all occasions...!

Wooscary · Post by **Wooscary** » Fri Nov 26, 2010 10:37 am

The amount of 11mms I always seem to find when all I need is a 10mm is surprising.

tim · Post by **tim** » Fri Nov 26, 2010 7:29 pm

The wife does have an 11mm in her Moto Guzzi toolkit but there are some things man was not meant to meddle with......

Post by **mat_fenwick** » Fri Nov 26, 2010 8:54 pm

Women?

Wooscary · Post by **Wooscary** » Wed Jun 01, 2011 3:06 pm

Sorry to drag this back, but just reread what had been said, and clearly I was being a bit dense, it all suddenly clicked and my HP belt is now nice and tight (actually I even fitted a new one!).

Many thanks for the advice.

rmattila · Post by **rmattila** » Wed Jun 01, 2011 3:32 pm

And while at it, check the tightness of the pump mounting pivot bolt nut. In my experience, it's the most usual cause for cracking of the high pressure supply pipe at the pump end union.

Wooscary · Post by **Wooscary** » Wed Jun 01, 2011 5:03 pm

Sounds worrying. I'm not sure which nut you mean. I think it's the one slightly lower than the pump, I undid this while tightening the belt and then did it up nice and tight again (it was really tight to start with).

rmattila · Post by **rmattila** » Wed Jun 01, 2011 5:23 pm

That's the one. I'm afraid I don't know the proper English term for it, but it's the one tightening the shaft along which the HP pump body rotates in the bracket when adjusting the belt tension. An M8 self-locking nut.

The one that was completely missing from Johnbird's pump in that incident.