EXUP Valve Bent (Bending back into place)

[Scottyboy]

Hi All,


As per the above, my EXUP valve is slightly bent thus not turning freely with the housing on causing the Full Monty to be locked away!


I understand people have straightened it using a vice and by hand - Curiously, is there a certain technique to doing this? Last thing I want to do is break the thing and fork out a crap tonne of money for a replacement.


Advise would be greatly appreciated.


Scott

[b1k3rdude]

Yeah, real simple. All you need is a variable speed hand drill and a rubber mallet.

• pop one end into the drill so that the vale is far in as it will go.
  
• then rotate the valve untill you see where is off-center, then gently wack the top with the mallet in the opposite direction, rince & repeat untill its centralized.
  
• remove the valve and put the other end into the drill as per steps, 1 and 2.
  

I did this a few years ago, took me all of 5 mins and got a perfectly straight valve.

[Tmation]

Mine was bowed the first time I serviced it, I just squeezed it straight between soft jaws in my dads engineers vice. I just put pressure on it a little bit at a time (squeeze then release)  a few times until it remained straight.

[Scottyboy]

Thanks for the advice, the variable speed drill shocked me with how much it was bent, to the naked eye it's hard to see just how much.


Smacked it a few times with a mallett - popped it back in as straight as we could get it and it still wouldn't turn.


Solution (And yes, it works a treat with no loose valve):


Took the spacer off the far end, added 2 small copper washers to enable little movement but a tad more room, also added a tiny washer to compensate on the plate end spindle. Moves freely, cables adjusted, opens and closes fine and my lord what an absolute animal.


Thanks for your help, I'll keep a close eye on it but for now, no knocking noises, no clanging, no rattling - Just pure POWAHHHHHHHH!


Scott

[b1k3rdude]

Smacked it a few times with a mallett - popped it back in as straight as we could get it and it still wouldn't turn.

Did you do with with both ends in the drill though..?

[Scottyboy]

Good point my man. What i'll do is monitor what we've done to it now, it works fine as it is. However, next time I have it out for a service, will give it a seeing too as per your suggestion.


Cheers bud.


Scott

[mark g]

Just out of curiosity how do they get bent in the first place??. I went to inspect mine the other day only to find nearly all the bolt head rusted beyond recognition, by the looks of things it's never been touched......BUT, it's running sweet even though it's coming up to 40k miles. I plan to leave sleeping dogs lie until the winter and get the header pipes off to a local engineering company to get the valve and all the old bolts out.

[Falcon 269]

Interesting tip with the drill ... I'll remember that one!

How they bend, I don't know - perhaps some distort through heat distortion if they seize in one place?

[b1k3rdude]

• Interesting tip with the drill ... I'll remember that one!
  
• perhaps some distort through heat distortion if they seize in one place?
  

• heh, cool. I came up with this method in my kitchen a years ago.
  
• exactly that.
  

[stevierst]

I had to straighten mine as the valve was seized when I got it.

Coming from an engineering background the drill and mallet technique made my hair stand on end! But if it works, then crack on.

I had to be a little bit more precise with mine, as it was jamming until it was perfectly straight. I had to use a straight edge and vernier caliper to get it right.

I clamped the central vane in the vice, and had to tweak each bearing surface a bit at a time with some long tubing which fitted over it. Just to correct the alignment, and get them running true.

I think I got them to within 0.1mm which seemed to work,but still squeaks on start-up every now and again.

[b1k3rdude]

Coming from an engineering background the drill and mallet technique made my hair stand on end! But if it works, then crack on.

Agreed, and had I access to a lathe and a dead flat surface I would have used them as that would have allowed me to be more precise.