Friday, 6 December 2019

CRC Rebuild - A Correction.......

Well. We're all learning, aren't we? Timo (T-Mo) contacted me with a query about my CRC rebuild from September 2018. This one HERE. Now there is very little information on how to rebuild and service a CRC unit. It's not really meant to be pulled apart. Okay, excuses over....

Timo's rebuilding his CRC and, as well as looking at my post, had been doing other research. How wise that turned out to be! He queried the order of the slide valve parts in my post as they seemed different to this diagram from Manual 843 - "Hydraulic Course Notes".
Inside the CRC Unit.....
The diagram shows part 8 sitting on the end of a spring and with it's thin end pushing on part 7 - the slide valve. In my blog I'd assembled the spring so that part 8 was inside the spring and went through it. Like this.....
This is how I thought it went....
And this.....
Push rod passed through the spring.....
I didn't want to pull the CRC off my car unnecessarily, but luckily I had a spare CRC that I was planning to rebuild. So I pulled it apart this afternoon to check, and this is what I found.......
NOTE: Thin end of the pin faces towards the slide valve deep inside
I nearly fell off my chair! I'd clearly assembled my CRC wrongly. Although the diagram that T-Mo was referring-to is only a schematic, not a technical drawing, the orientation of parts in this second CRC looked far more like it.

Now I should have known better for several reasons. Firstly, I should have taken more reference photos for my strip and rebuild. Secondly one of the reference photos that I found and salted away after my rebuild clearly showed the parts in a different order.......
An efi CRC - photo clearly shows which way round the push rod goes....
So that seems to confirm it. Anyway, my thanks to T-Mo for bothering to query my post and not assuming everything he was reading was correct.

My penance? Well apart from going back to correct my original blog, I've now got to pull the CRC from the car and rebuild it again.....