CRC Rebuild - The Riddle of the Seals - Solved!

If you've read my 29 September 2018 post about rebuilding a CRC unit, you will know that my repair kit seem to have an extra 'spare' seal in it. Surely that wasn't right?

I'd done a pretty comprehensive strip of my CRC, but had ducked-out of pressing out the shaft with the cam on. I couldn't really see how it came out or went back together, so thought it best not to disturb it.

Strip Down

Preparing for the rebuild, I started to account for the parts in my kit. I had a spare 'O' ring! 

Where did the mystery seal go?

Was it a mistake in the kit? I checked a few other kits and they too seemed to have one seal more than I could account-for. In fact the kits varied greatly: some included the hook ended springs, others didn't. The CRC on an IE car doesn't have the flow restrictor ball bearing - though at least one of the kits I found included a bearing. It was all a bit of a lottery.

Seal kit bingo.......

Having accounted for everything else, I was pretty sure that the seal was something to do with the rotating shaft, though I couldn't think why an IE car would have the seal but a carb car wouldn't. The shaft seemed to be the kind of thing that should be sealed, but I would have perhaps expected it to have two seals - one either end? However of all the kits I looked at, I could only find one 'O' ring without an obvious home...... 

I made some enquiries about the differences in the kits and had some interesting ideas in response. One person I spoke-to thought the extra one went onto the end of the pipe that the return hose is connected to. Another thought it was an 'anti-rattle' fitting that went between the CRC and the inlet manifold. Another just thought it was included as a handy spare (for what?).

Unconvinced by these ideas, I left the last, spare 'O' ring off. I got the CRC all back together again but that extra 'spare' 'O' ring niggled me. 

It must go somewhere? I carefully put it away in a box. I was keen to get to the bottom of this and shortly after my rebuild I got a response to the thread I had started  over at 'Aussiefrogs'.  Firstly 'Myourd' posted that he'd knocked the shaft out of a CRC and had found a seal. A day or so later Michael ('Michaelr') posted a photo. It solved the riddle of that last seal!

Here's the photo. You can see that the single, black seal fits into a groove on the rotating shaft.

Location of the mystery seal revealed!

So - how to get at that seal? There is a bush on the end of the shaft that does not connect to the carburettor - so the other end. It looks as though the bush (on the right hand side of the picture above) has been pulled off the shaft with mole grips or similar. It looks quite chewed up. More recently I have seen photos of work done on the CRC by 'Timo'. It looks as though he welded a length of threaded rod to the end of the bush and then, by rigging up a nut and spacer around the bush with a piece of tube......

Using a nut to wind off the seal bush (photo by Timo)

.......slowly wound the bush out. Very much like pulling the cork out of a bottle of wine. You can see the bush and welded rod at the bottom of the photo below.

Bush with welded threaded length (photo by Timo)

With a bit of cleaning up, I reckon that bush could be re-used for the rebuild after replacing the seal.

Going back to Michaelr's photo, you can also see that the 'O' ring seal ion the removed shaft looks quite worn and flat. Maybe it leaks.... 

The spare CRC I'd bought at Citromobile was covered in silicon sealant and it was very likely that was because it leaked in some way. Maybe because it lacked the gasket between the two halves, but maybe that difficult-to-get-at last seal was the culprit?

Smeared-on silicon sealent points to a problem of some kind....

The photo from 'Michaelr' was also helpful in another way. Now when people say they need another CRC, they often say the reason why is that the rotating shaft has become stiff or 'knotty'. If you turn them by hand, they do get a bit knotty and 'lock' - reluctant to return. Here's  a link to a video of someone demonstrating this:

Demo of a 'knotty' CRC Unit

Anyway, when the CRC is fitted to the car (on a carburettor car at least), the return springs of the throttle pedal help with that 'return' action. However, it wouldn't hurt to make sure there are no flat spots on the cam.

From my own rebuild, I noticed that the cam was slightly worn and wondered whether it had developed a flat spot and whether it would perhaps benefit from a polish. However as I wasn't confident about getting the cam off, I had to leave that thought there. Seeing Michaelr's photo now, helped to demystify this part of the puzzle for me: I could see that the cam fits to splines on the shaft.Not so sure about that chewed-up part on the right side of the photo though.

As I've got a spare CRC, perhaps I'll buy another rebuild kit and go the whole hog this time - replacing that 'spare' seal and polishing the cam.

Textar Brake Pads - The Gentleman of Verona

A very exciting parcel has arrived from Italy! I wonder what’s in it?

I love a good parcel - especially when it's from abroad and DS-related

Actually I know what’s in it, I’m just trying to build some mystery and suspense.

Now if you look elsewhere, and can find them, a set of genuine original Textar brake pads is going to cost you about £250. When I was over at the Citromobile thing in Holland back in May, I found a set of Textar brake pads for just 80 Euros !! 

Lovely Textar brake pads.......

That part’s true, but there is a down side (I was just trying to build suspense again). The down side? It was a part-worn set. But they looked as good as new. They’d come from a car that had crashed.

The seller was Italian. Several attempts were made at a joke with the seller along the lines of “I hope the brakes weren’t the cause” but it was completely lost in translation. Anyway, genuine Textar brake pads for 80 Euros - bargain! I was literally counting out the money to buy them when I suddenly spotted that they didn’t have the brake wear warning light wires fitted - did you spot that? They still had the holes for the wires, but they had not been fitted and instead glue or filler was squidging out of the holes. 

Textars: with and without wires for the brake wear indicators......

Prior to the 1969 model year, IDs did not have the wiring to the dash for the brake wear indicator in their loom - it was a DS-only thing. So not all pads needed to have the corresponding wires in them.

Pre-69 ID loom without brake wires

Pre-69 DS loom with brake wires

So no wires. Money hadn’t changed hands. The pads would have been absolutely fine, but I decided to hold on to my money and keep looking for a set with the wires. The deal was off! (more suspense building again). 

I came back to the UK and, as is my way, realised that I could use those Textar pads after all……..  I realised that I could carefully remove the wires from my dead set of pads and re-fit them in the 'tunnels' of the pads I’d seen.

A plan to re-fit the wires.......

The wires are a non-critical component of the pads themselves. They don’t come under any strain or load. They simply sit there, then trigger a 'wear' warning light once the wire inside is earthed against the brake disc. The wire lies in a groove between the backing plate and the pad - a tunnel - and looks as though it is simply held in place by whatever glue is used to bind the brake pad to the backing plate.  From what I remember seeing at Ciromobile, I was gambling on the mould for all Textar pads having the wire groove in the back. I’d just need to carefully clean out the tunnels with a twist drill. I decided I could then use exhaust sealing paste as the glue for the new wires: it’s non-sticky but dries hard and is able to withstand high temperatures. It crumbles to a dust when put under pressure or scraped.

I tested the tunnel theory. I didn’t want to drill into the pad itself - for fear of weakening it. I just wanted to clean out what I was sure would be existing holes. One of my old split pads served to help me align the drill to the correct angle of the tunnel - which was helpful. What I found though, was that the body of the brake pad would block the chuck and would prevent the drill bit going deep enough to clean the holes out.....

The drill isn't long enough

I did a bit of research and found some extra long drills over in China. They are probably not the best quality but only have to do a simple job and are very cheap. Problem solved!

Solution: extra long drills......

Okay: I had a plan. I just needed to put it in to action. The parts seller at Citromobile was Italian and I vaguely remembered where his stall was. Using the programme I tried to work out who it was. 

Citromobile 2019: the stall was somewhere around here. The suspense is killing me......

I remembered an Italian guy who was always at Citromobile and always at the same place - and approximately where I remember seeing those brake pads. Stall 107 - Citro Services! I Googled them and sent off an email.

Wrong guy……I looked more closely at the Citromobile floor plan......I did a bit of digging and came up with a possible alternative name: Perencin - stall 145. He sold DS parts. There were no contact details in the Citromobile programme and a Google search of the given trade name - "Citroen DS Parts Perencin" - drew a blank - other than confirming a probable Italian connection for the name in general.

My research revealed that a "Riccardo Perencin" had also had a stall at the ICCR up at Harrogate a few years ago, but again no contact details. Even though I was narrowing in on a name, I was still struggling for contact details and Riccardo seems to have a low internet profile. I think the breakthrough came from some old forum posts on a German DS site. Riccardo is based in Verona. More digging and I finally came up with a possible email address.

After some heavy use of Google translate and few emails, the deal was back on! The purchase was made and the pads have now arrived. I’m very pleased with them. They have just over 14mm of pad depth on them. I compared that to a brand-new, un-used set of Ferodo pads that I have: they have less than 12mm pad depth from new.

Textar (on the left) still has good pad depth

And, just as I remembered it to be, these Textar pads do indeed have the little holes where the brake-wear indicator wires go - they’ve just been filled in. 

You can see the hole where the wear indicator wire should go

In all other respects, they’re the same as my old Textar pads and carry the same part number.

My drill bits are currently on a slow boat. As soon as they arrive  I will set to work fitting those wires. I’ll keep you posted.