Dressing The Engine (Part 3) - Ancillaries, Pulleys and Belts

Fitting The Ancillaries

As several functions of the car are belt driven, fitting the ancillaries means aligning them and, more importantly, their pulleys.

The first job was to mount the ancillaries: HP pump, centrifugal regulator and alternator. While I had the access, I used a ‘Mirex’ buckle to connect the main LHM feed hose to the top of the HP pump, before introducing it to the car. 

I’d already cleaned and primed the bracing bars for the HP pump and centrifugal regulator several years ago. These now got a coat of black paint. Similarly, I had already zinc plated the various nuts bolts and washers. I’d taken several reference photos to show how these, and the spacers and bushes, fitted on the bracing bars.

Before: Centrifugal Regulator - September 2015

I couldn't fit the drive belts at this stage so just set the approximate positions of the ancillaries and their bracing bars.

With the HP pump fitted, I was able to refit the 6.35mm pipe to it from the pressure regulator. 

Hydraulic Pipe to HP Pump

In doing this, I discovered I had the wrong hydraulic rubber seals. There are two sizes. While the inner diameters are the same, The outside diameter of mine were approximately 12mm. 

Both are 6.35mm seals, but the one on the left is 12mm outer

These are used on the 6.35mm pipe that goes to the brake accumulator. They proved too big, (and so too tight), for the HP pump and pressure regulator. Instead I had to get hold of some correct 10mm outer diameter seals.

Fitting the alternator was straightforward. As each component was fitted, the various lugs and holes cast into the bell housing started to make increasing sense. 

The fitting of the centrifugal regulator was a little more tricky – possibly because of it’s rubber ‘silent bloc’ mountings. As there is some longitudinal movement afforded by the silent blocs, there are a number of spacers and shims that can be fitted to the fixing bolt to give the right position on the water pump housing. 

It was quite fiddly dropping the washers into place and capturing them on the bolt while balancing the weight of the regulator.

As with the HP pump I just did a loose fit of the mounting bolt and bracing bar until I had checked pulley alignment.

I’ve seen several cars with the bracing bar for the centrifugal regulator fitted wrongly – usually upside down. The end with the hole and rubber bush should go at the top.

Reference Photo - Spring 2015: top end of bar - with rubber bush

This then means the slot end is at the bottom. The benefit of getting it the right way up is that the slot is meant to provide an extra mounting point for an extra nut, bolt and bracket to hold the hydraulic pipes that comes from the top of the centrifugal regulator.

Bottom end of bar - with extra mounting bolt

Pulley Alignment

Pulley alignment is covered in Operation DX.231-0 in Manual 518 and Operation D.236-0 in Volume 1 of  Manual 814.

As the water pump is an integral part of the cylinder head, it is regarded as the baseline component from which reference alignment is taken. There are different sources of pumps and the pulley of the water pump is ‘spun on’ to the pump shaft (rather than being bolted) so even then there is some variation in pulley position: if you swap out the water pump, you should really re-check its continuing alignment to other units and, if you adjust one, you probably then need to adjust another…….

For a bvh car the aligning order is as follows:

-        Alignment between water pump pulley and large grooves of camshaft pulley

-        Alignment between waterpump pulley and alternator pulley

-        Alignment between small grooves of camshaft pulley and HP pump

-        Alignment between HP pump and centrifugal regulator.

There are a couple of different Citroen tools for checking the alignment of pulleys. I used a homemade alignment tool.

The drive belts are 9.5mm width. I had bought some 8mm rod (so that it would sit comfortably in a pulley groove) and (having checked that the rod was straight and true), bent one end (carefully) about 170 degrees around a spare pulley from a centrifugal regulator to give something of a parabolic curve. 

Having shaped the rod, I then re-checked it on a flat surface to make sure that the curved part and long end were still flat/ true.

The hook-shaped end meant that the rod would settle and sit in the groove of a number of different sized pulleys in at least two places – which reduces wobble/ freeplay  and so increases the likelihood of it being  perpendicular to the pulley shaft. As it is the baseline component, I thought about forming it around an old water pump pulley - but then that curve would have been too big/ loose for fitting to the HP pump and centrifugal regulator.

Tool Fits Other Pulleys Too

Water pump to camshaft pulley: My home made tool was slotted over the water pump pulley as it was the smaller of the two. I already had a shim on the shaft between the bearing and the camshaft pulley pulley and found that still gave the right alignment with my new water pump.

Camshaft Pulley Alignment

Water pump to alternator: alignment here was also fine. so far, so good.....

Alternator Lined Up Okay

Camshaft pulley to HP pump: The alignment tool was slotted over the the back grooves of the camshaft pulley. The HP pump was out and needed shimming........

The HP pump, and so its pulley, was out of alignment

I temporarily put a couple of washers between the pump and the mounting log to get the correct alignment, but I plan to get washers with a larger outer diameter to provide better support for the pump.

Temporary shims on the HP Pump

HP Pump to centrifugal regulator: Lastly, the tool was fitted on the HP pump and aligned to the centrifugal regulator.....

Checking the alignment of the centrifugal regulator

If the HP pump was out of alignment, then it probably meant the centrifugal regulator was also out of alignment. Yep......but not as much as the HP pump had been.

Regulator Pulley Was Out Of Alignment

The centrifugal regulator has a spacer behind the front mounting point. These were available in several different sizes, though I didn’t have a bag of these laying around. If – to get alignment – the spacing at the front is altered, then you also need to vary the shims and other washers at the back mounting point. In my case I needed to move the regulator forward by taking a couple of shims out from the back mounting point. and putting them at the front with the spacer.

Shims on the centrifugal regulator

This was quite fiddly to do because of limited access around the bolt shaft. The alignment was checked again.......That was better.

The Pulley Now Aligned

Drive Belt Tensioning

The camshaft pulley and several brackets were removed to allow me to slip the drive belts on. A rummage around in my parts boxes revealed that (with the pair of belts I bought at the DS rally this year) I now had a complete set of new Kleber ‘Ventiflex’ belts......

Drive Belt Set For My bvh car

........including two matched pairs. Result!

Matched Pair of Drive Belts

Being a hydraulic gearbox car, my car has five 9.5mm width belts. These are:

·    Pair of belts (ideally a matched-length pair) between the camshaft pulley and the HP pump (mine are length 790/ 800mm)

Single belt from the HP pump to the centrifugal regulator (mine is length 600mm)

Pair of belts (ideally a matched-length pair) between the camshaft pulley, alternator and water pump/ fan (mine are length 955/ 965mm. 975mm length is better)

With the pulley alignment checked and set, I slipped the pair of HP pump belts on the camshaft, refitted the clutch cylinder rod, then bolted on the camshaft pulley. The camshaft pulley nut was tightened and the edge of the nut knocked over into the groove in the shaft to stop it working loose.

The remaining belts were refitted and the ancillaries and their bracing bars re-adjusted to provide a little tension on these.

Pulleys Aligned and Belts Fitted

All Belts On

After: Centrifugal Regulator - October 2018

Although the belts were now on, I will do a ‘final fix’ of these components later in the build. The order for tensioning the drive belts and their respective tensions is given in Operation D.236-0 in Volume 1 of  Manual 814 and/ or Operation DX.231-0 in Manual 518.