1 Attachment(s)
Zd30 crd rail relief valve test and replacment
Ok so there might be something like this about but I thought I’d share what happened to me.
So I set out to test if my common rail relief valve was holding rail pressure, refer the the image
Start by removing the engine cover and inter cooler.
Then I took the hose #3 off the fitting as that is the injector leak back hose and I didn’t want that fuel messing with my resaults.
Then I cranked the engine and as it ran I saw fuel coming from the hose (this is normal it’s injector leak back) I also saw fuel coming from when the hose connected. I I thought relief valve is shot and needs to be swapped. I have spares of these so I fitted one.
How to fit relief valve
17mm spanner on the nut #1 that way I had access to the valve itself #2 again 17mm spanner here and it was tight but not un-humanly tight. Then reverse and should be done.
I carried out my test again and I found fuel still coming from the barb which the leak back hose was connected to.
It was at this point I thought fuel must be coming from the pipe on the right side of #4 banjo bolt. To test this I took out the banjo bolt. (Be carful not to loose the copper washer on each side of the fitting.)
After this was apart I ran the engine and I had no fuel coming from the rail, which mean the relive valve was in fact holding and all good. But I was getting fuel from the metal pipe the runs to the right of #4 banjo bolt piece.
So I’m wondering if the original relief valve was stuffed or not as my original test was not right. Either way the new valve in I feel it’s better I don’t know it it’s In my head or not but I’m which is the main thing.
Not too sure why fuel was coming from this pipe though?
Thought I’d post this so others can learn from my mistake of incorrectly testing the valve. As originally my resaulst were invalid as the fuel I suspected leaking from the relief valve was in fact coming from the metal pipe that I stated above.Attachment 77077
