Welcome to the Connecticut Z Car Club Forums




Username:  
Password:  
Log me on automatically each visit
Register 
It is currently Fri Nov 16, 2018 11:19 pm
Welcome to the Connecticut Z Car Club Discussion Forums   
If you have trouble logging in or encounter any issues, please send an email to webmaster@ctzcc.com.

All times are UTC - 5 hours





Post new topic Reply to topic  [ 4 posts ] 
  Print view Previous topic | Next topic 
Author Message
 Post subject: Water pump Journey
PostPosted: Mon May 20, 2013 8:33 pm 
Offline

Joined: Thu Oct 11, 2012 6:48 pm
Posts: 381
Location: Stamford, CT
BACKSTORY: When I was about to buy my new 240Z the previous owner said the water pump needed to be changed but I was running a little late and he had the time so he changed it himself. Everything had been fine until I noticed that in traffic my car would start to overheat. Upon further examination and guidance by Frank, I installed a missing thermostat and better flowing radiator from Zorro right before the fun run, but the temp gauge always showed that the car was running hot even after cruising at low RPMs in 5th in 50 degree weather.

ISSUE: A few minutes after bringing the car up to 6k during the fun run I noticed that the temp gauge was past the red but I assumed that the temp gauge/sender was acting up. A few minutes later the car started smoking and we pulled over

Image
Image

Eventually realized that the car had been leaking coolant from the bottom of the water pump and the radiator was dry. Got it back home with the help of Zorro, a kind stranger, and RTV silicone. Took the water pump and found this:
Image
Blown gasket!
While taking the water pump off, I noticed that the lowest bolt for the water pump could spin freely and this is what the threads looked like:
Image
Realized that a bolt from my 260Z's water pump arm had the same threading but was a bit longer so I threw a ton of washers on it and began to tighten it. It was about to get as tight as the other bolts when I hear a snap and the bolt slackens :shock:. Pulling it out revealed this:
Image
The threads on the end are completely gone! I later noticed that the previous bolt had the same issue but on a smaller scale since it wasnt as long. Right now the car is running fine as it did before with a new gasket, but I am missing the lower bolt which opens the possibility of blowing another water pump gasket. MSA sells a water pump bolt kit, but I dont want to buy it if the threads on my lower bolt are just going to get eaten again. Any idea what could be causing this problem?

_________________
71' 240Z: HLS3040666

Albums:
https://plus.google.com/+FlyingAero
Youtube:
http://www.youtube.com/user/FlyingAero


Top
 Profile  
 
 Post subject:
PostPosted: Tue May 21, 2013 7:38 am 
Offline

Joined: Tue May 20, 2008 8:03 am
Posts: 168
Can you chase it with a tap or thread restore kit? Also, is the old bolt snapped off inside somehow or did it come out completely? You might have to remove the old pieces if they're stuck inside.

_________________
280zx NA to T... http://z.modeltrainguide.com


Top
 Profile  
 
 Post subject:
PostPosted: Tue May 21, 2013 10:00 am 
Offline

Joined: Wed Apr 09, 2008 5:53 pm
Posts: 12934
Location: CT
The remedies for deep-set broken bolts include drilling them out with increasing-size drill bits. I suspect the PO started to do that job, but quit before he actually removed the broken stub of the original bolt.

I *think* that shorter bolt is the original broken bolt. The end of it is probably still fully seated in the bolt hole, but now it has a 'cup' drilled into the center of it. It would be ragged around the edges, so trying to insert another (longer) bolt into the hole would chew up the end threads, just like you're showing on your second picture. Just a guess.

Step One would be to clean out that bolt hole and ensure you've removed the broken-off stub which I suspect is still in there.

If you mangle the threads along the inside of the bolt hole, you can try to dress them up (first) with a follow-up tap of the same thread count. If that works, you simply use a new bolt and gasket and your job is done.

If the threads are mangled beyond redemption, you simply drill them all out, re-size the hole and re-tap it with a larger thread diameter, then use the appropriate threaded bolt to replace the old one. Most of us use SAE bolts as replacements, since they're easier to find here. Your restriction would be the size of the hole in the pump housing itself ~ in other words, the bolt still has to be skinny enough to pass thru the pump housing, then screw into the engine. I've actually seen guys hone open the hole in the pump to allow them to use a fatter bolt.

_________________
1970 240Z


Top
 Profile  
 
 Post subject:
PostPosted: Tue May 21, 2013 10:06 am 
Offline

Joined: Sat Feb 16, 2013 3:42 pm
Posts: 282
Location: Rochdale, MA
Here is some good info if enlarging the hole and retapping larger isn't an option....

http://www.fjr1300.info/howto/helicoil.html

I feel though the hardest part is removing the broken bolt and not the thread repair.

_________________
Adam Perry
Datsun 260Z
Image


Top
 Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 4 posts ] 

All times are UTC - 5 hours


Who is online

Users browsing this forum: No registered users and 3 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  
cron









Powered by phpBB © 2000, 2002, 2005, 2007 phpBB Group
mile200 v1.0.1 designed by Team -Programming forum- .