Ford Sierra/Sapphire/RS500 Cosworth This forum is for discussion of all things pertaining to the Ford Sierra Cosworth.

leak down?

Thread Tools
 
Search this Thread
 
Old 09-06-2009, 02:32 PM
  #1  
coachworz
Regular Contributor
Thread Starter
 
coachworz's Avatar
 
Join Date: Jul 2007
Location: Singapore
Posts: 325
Likes: 0
Received 0 Likes on 0 Posts
Default leak down?

what does cylinder leak down mean? and how does that happen?
Old 09-06-2009, 04:06 PM
  #2  
tabetha
20K+ Super Poster.
 
tabetha's Avatar
 
Join Date: Jul 2006
Location: uk
Posts: 24,596
Likes: 0
Received 3 Likes on 3 Posts
Default

It's just compressed air is fed into a cylinder, and the amount of time it takes for the pressure to subside is measured, can give a lot better indication of some conditions than a std compy test.
tabetha
Old 10-06-2009, 01:04 AM
  #3  
coachworz
Regular Contributor
Thread Starter
 
coachworz's Avatar
 
Join Date: Jul 2007
Location: Singapore
Posts: 325
Likes: 0
Received 0 Likes on 0 Posts
Default

mine got 50% leak down on 2,3,and4 cylinder!
Old 10-06-2009, 08:52 AM
  #4  
cossie604
PassionFord Post Whore!!
iTrader: (2)
 
cossie604's Avatar
 
Join Date: Apr 2005
Location: Derby
Posts: 4,703
Likes: 0
Received 2 Likes on 2 Posts
Default

The great thing about doing a leak down test is you can pin point the fault ie rings, inlet/exhaust valves or headgasket with out dismantling the engine...unlike a standard compression test that basicaly just tells you its down.
Old 10-06-2009, 05:44 PM
  #5  
kirky
Regular Contributor
 
kirky's Avatar
 
Join Date: Mar 2006
Location: CLEVELAND RSOC
Posts: 270
Likes: 0
Received 0 Likes on 0 Posts
Default

what tool do you use to do this test as i would like to do mine???
Old 10-06-2009, 08:55 PM
  #6  
cossie604
PassionFord Post Whore!!
iTrader: (2)
 
cossie604's Avatar
 
Join Date: Apr 2005
Location: Derby
Posts: 4,703
Likes: 0
Received 2 Likes on 2 Posts
Default

Mines a proper snap-on set up with a gauge. You can buy cheap versions that do exactly the same for around 30-40quid......but tbh you can make one also. Get an airline adaptor, a old spark plug and a peice of metal pipe. Smash the plug electrode out so you've just got a threaded part with a hole straight through. Weld the metal pipe to this then weld the airline adaptor on the end....just so you can fill the cylinder with compressed air. Set the piston at tdc on the compression stroke, leave it in gear with the handbrake on and hook up the air line to the fitted adaptor. You wont have a gauge but you can listen/look for the leaks. Oil filler cap off or dip stick out to gauge ring blow-by, ear to exhaust tail pipe to listen for a leaky ex valve, ear to inlet for inlet valve and Ive even managed to find a headgasket failure in the past by air bubble's in the header tank.

Last edited by cossie604; 10-06-2009 at 08:56 PM.
Old 11-06-2009, 08:11 AM
  #7  
kirky
Regular Contributor
 
kirky's Avatar
 
Join Date: Mar 2006
Location: CLEVELAND RSOC
Posts: 270
Likes: 0
Received 0 Likes on 0 Posts
Default

is this the gauge to use???

http://buy1.snapon.com/products/diag...s/eepv309a.asp

Trending Topics

Old 11-06-2009, 08:20 AM
  #8  
cossie604
PassionFord Post Whore!!
iTrader: (2)
 
cossie604's Avatar
 
Join Date: Apr 2005
Location: Derby
Posts: 4,703
Likes: 0
Received 2 Likes on 2 Posts
Default

Nothing like mine but yeah, thats what your after.
Old 11-06-2009, 08:24 AM
  #9  
cossie604
PassionFord Post Whore!!
iTrader: (2)
 
cossie604's Avatar
 
Join Date: Apr 2005
Location: Derby
Posts: 4,703
Likes: 0
Received 2 Likes on 2 Posts
Default

Just looked on ebay and the cheapies are around Ł60....I think I must have sold my old spare one for around Ł30, hence where I got that price from in my head.

There's this one....

http://cgi.ebay.co.uk/Sykes-Pickavan...3A1%7C294%3A50
Old 11-06-2009, 08:39 AM
  #10  
kirky
Regular Contributor
 
kirky's Avatar
 
Join Date: Mar 2006
Location: CLEVELAND RSOC
Posts: 270
Likes: 0
Received 0 Likes on 0 Posts
Default

cheers for that!!!
Old 11-06-2009, 09:04 AM
  #11  
fraser9764
PassionFord Post Troll
iTrader: (3)
 
fraser9764's Avatar
 
Join Date: Oct 2006
Location: Cheshire
Posts: 3,070
Received 30 Likes on 24 Posts
Default

i made one using the above method, apart from i tapped a 1/4 bsp thread into the remains of the spark plug and wound in a barrel nipple and make some adapters up to take an air line. worked perfectly for me, one completely fooked head
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
timsrs
Ford Sierra/Sapphire/RS500 Cosworth
5
13-11-2018 11:48 AM
Fudgey
General Car Related Discussion.
21
30-09-2015 06:19 PM
wheelwizardrefurbs
Technical help Q & A
1
21-09-2015 06:42 AM
talon1
Technical help Q & A
0
15-09-2015 10:27 AM
BRAMMER
Ford Sierra/Sapphire/RS500 Cosworth
15
14-09-2015 08:52 PM



Quick Reply: leak down?



All times are GMT. The time now is 11:23 PM.