Steve Foley

How is a leak down test done?

The one done on small aircraft engines involves pumping 80PSI into the
cylinder and reading the remaining pressure off a gauge. The results are
given as 77/80, 76/80, 79/80, 80/80.


"Greg" <greglc84@hotmail.com> wrote in message
news:m11ye.153949$El.26712@pd7tw1no...
> Don't know about the windsheild, but 160 accross on the engine sounds
> good, sounded good on mine too till we did a leak down test, 15, 18, 22,
40,
> 49, 15, 20, not so good
>
> "Lee Ayrton" <layrton@panix.com> wrote in message
> news:daa3tf$7l3$1@reader2.panix.com...
> >
> > Posting for a friend with a 1984 CJ, 258, std. that he's rebuilding.
> >
> > What's the spec for cylinder compression? He's getting 160 across all 6
> > cyls, which sounds pretty good from here.
> >
> > He's putting a new fiberglas tub on his Jeep and might have a windshield
> > frame from a Wrangler fall into his lap, which was offered to him as
> > having a better wiper system than the CJ. Will this fit the tub without
> > causing problems with his hard top? I gather that there may be bolt
hole
> > and vent issues, but since he's putting a new tub on anyway it might not
> > matter. Will his existing scratch-and-chip-free windshield glass fit
the
> > Wrangler frame?
> >
> > Thanks.
> >
> >
> >
> >
> >
> >
>
>

Steve Foley

How is a leak down test done?

The one done on small aircraft engines involves pumping 80PSI into the
cylinder and reading the remaining pressure off a gauge. The results are
given as 77/80, 76/80, 79/80, 80/80.


"Greg" <greglc84@hotmail.com> wrote in message
news:m11ye.153949$El.26712@pd7tw1no...
> Don't know about the windsheild, but 160 accross on the engine sounds
> good, sounded good on mine too till we did a leak down test, 15, 18, 22,
40,
> 49, 15, 20, not so good
>
> "Lee Ayrton" <layrton@panix.com> wrote in message
> news:daa3tf$7l3$1@reader2.panix.com...
> >
> > Posting for a friend with a 1984 CJ, 258, std. that he's rebuilding.
> >
> > What's the spec for cylinder compression? He's getting 160 across all 6
> > cyls, which sounds pretty good from here.
> >
> > He's putting a new fiberglas tub on his Jeep and might have a windshield
> > frame from a Wrangler fall into his lap, which was offered to him as
> > having a better wiper system than the CJ. Will this fit the tub without
> > causing problems with his hard top? I gather that there may be bolt
hole
> > and vent issues, but since he's putting a new tub on anyway it might not
> > matter. Will his existing scratch-and-chip-free windshield glass fit
the
> > Wrangler frame?
> >
> > Thanks.
> >
> >
> >
> >
> >
> >
>
>

Steve Foley

How is a leak down test done?

The one done on small aircraft engines involves pumping 80PSI into the
cylinder and reading the remaining pressure off a gauge. The results are
given as 77/80, 76/80, 79/80, 80/80.


"Greg" <greglc84@hotmail.com> wrote in message
news:m11ye.153949$El.26712@pd7tw1no...
> Don't know about the windsheild, but 160 accross on the engine sounds
> good, sounded good on mine too till we did a leak down test, 15, 18, 22,
40,
> 49, 15, 20, not so good
>
> "Lee Ayrton" <layrton@panix.com> wrote in message
> news:daa3tf$7l3$1@reader2.panix.com...
> >
> > Posting for a friend with a 1984 CJ, 258, std. that he's rebuilding.
> >
> > What's the spec for cylinder compression? He's getting 160 across all 6
> > cyls, which sounds pretty good from here.
> >
> > He's putting a new fiberglas tub on his Jeep and might have a windshield
> > frame from a Wrangler fall into his lap, which was offered to him as
> > having a better wiper system than the CJ. Will this fit the tub without
> > causing problems with his hard top? I gather that there may be bolt
hole
> > and vent issues, but since he's putting a new tub on anyway it might not
> > matter. Will his existing scratch-and-chip-free windshield glass fit
the
> > Wrangler frame?
> >
> > Thanks.
> >
> >
> >
> >
> >
> >
>
>

Mike Romain

The compression is too high or the gauge is bad. A 'new' 258 is only
supposed to have 150. (carboned up or shaved head?)

As mentioned, the vents are different on the frames if it is a 'stock'
frame. If aftermarket they fit both but you 'really' have to check the
post for the driver's side wiper to make sure it is in the right place
and the sheet metal around it is not not bent. There are a pile of bad
ones on the aftermarket. The result of the poor wiper arm post fit is a
jam and a burn out of the motor or intermittent module smoke out with
bent linkages.

I was given one also when I did my 'glass tub and it was already crapped
out and sheet metaled over that hole to move it. I bought a new one and
got the same crappie fit. I eventually had to cut the hole out of my
old
frame and move it over to the new frame to position it right after a
couple years of messing around with washers and cursing when it died on
the highway in the rain.

Tell him not to forget to ground the windshield frame itself! The
hinges have this nasty tendency to not want to be ground points for the
wipers about half way through bogs as I found out on a trip 1000 miles
from home in a Nova Scotia bog with 3500 miles left to get back
home.... Figured it out pretty quick but getting the rest of the way
through that bog with my head out the door to see was messy....

Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's

Lee Ayrton wrote:
>
> Posting for a friend with a 1984 CJ, 258, std. that he's rebuilding.
>
> What's the spec for cylinder compression? He's getting 160 across all 6
> cyls, which sounds pretty good from here.
>
> He's putting a new fiberglas tub on his Jeep and might have a windshield
> frame from a Wrangler fall into his lap, which was offered to him as
> having a better wiper system than the CJ. Will this fit the tub without
> causing problems with his hard top? I gather that there may be bolt
> hole and vent issues, but since he's putting a new tub on anyway it
> might not matter. Will his existing scratch-and-chip-free windshield
> glass fit the Wrangler frame?
>
> Thanks.

Mike Romain

The compression is too high or the gauge is bad. A 'new' 258 is only
supposed to have 150. (carboned up or shaved head?)

As mentioned, the vents are different on the frames if it is a 'stock'
frame. If aftermarket they fit both but you 'really' have to check the
post for the driver's side wiper to make sure it is in the right place
and the sheet metal around it is not not bent. There are a pile of bad
ones on the aftermarket. The result of the poor wiper arm post fit is a
jam and a burn out of the motor or intermittent module smoke out with
bent linkages.

I was given one also when I did my 'glass tub and it was already crapped
out and sheet metaled over that hole to move it. I bought a new one and
got the same crappie fit. I eventually had to cut the hole out of my
old
frame and move it over to the new frame to position it right after a
couple years of messing around with washers and cursing when it died on
the highway in the rain.

Tell him not to forget to ground the windshield frame itself! The
hinges have this nasty tendency to not want to be ground points for the
wipers about half way through bogs as I found out on a trip 1000 miles
from home in a Nova Scotia bog with 3500 miles left to get back
home.... Figured it out pretty quick but getting the rest of the way
through that bog with my head out the door to see was messy....

Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's

Lee Ayrton wrote:
>
> Posting for a friend with a 1984 CJ, 258, std. that he's rebuilding.
>
> What's the spec for cylinder compression? He's getting 160 across all 6
> cyls, which sounds pretty good from here.
>
> He's putting a new fiberglas tub on his Jeep and might have a windshield
> frame from a Wrangler fall into his lap, which was offered to him as
> having a better wiper system than the CJ. Will this fit the tub without
> causing problems with his hard top? I gather that there may be bolt
> hole and vent issues, but since he's putting a new tub on anyway it
> might not matter. Will his existing scratch-and-chip-free windshield
> glass fit the Wrangler frame?
>
> Thanks.

Mike Romain

The compression is too high or the gauge is bad. A 'new' 258 is only
supposed to have 150. (carboned up or shaved head?)

As mentioned, the vents are different on the frames if it is a 'stock'
frame. If aftermarket they fit both but you 'really' have to check the
post for the driver's side wiper to make sure it is in the right place
and the sheet metal around it is not not bent. There are a pile of bad
ones on the aftermarket. The result of the poor wiper arm post fit is a
jam and a burn out of the motor or intermittent module smoke out with
bent linkages.

I was given one also when I did my 'glass tub and it was already crapped
out and sheet metaled over that hole to move it. I bought a new one and
got the same crappie fit. I eventually had to cut the hole out of my
old
frame and move it over to the new frame to position it right after a
couple years of messing around with washers and cursing when it died on
the highway in the rain.

Tell him not to forget to ground the windshield frame itself! The
hinges have this nasty tendency to not want to be ground points for the
wipers about half way through bogs as I found out on a trip 1000 miles
from home in a Nova Scotia bog with 3500 miles left to get back
home.... Figured it out pretty quick but getting the rest of the way
through that bog with my head out the door to see was messy....

Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's

Lee Ayrton wrote:
>
> Posting for a friend with a 1984 CJ, 258, std. that he's rebuilding.
>
> What's the spec for cylinder compression? He's getting 160 across all 6
> cyls, which sounds pretty good from here.
>
> He's putting a new fiberglas tub on his Jeep and might have a windshield
> frame from a Wrangler fall into his lap, which was offered to him as
> having a better wiper system than the CJ. Will this fit the tub without
> causing problems with his hard top? I gather that there may be bolt
> hole and vent issues, but since he's putting a new tub on anyway it
> might not matter. Will his existing scratch-and-chip-free windshield
> glass fit the Wrangler frame?
>
> Thanks.

Mike Romain

The compression is too high or the gauge is bad. A 'new' 258 is only
supposed to have 150. (carboned up or shaved head?)

As mentioned, the vents are different on the frames if it is a 'stock'
frame. If aftermarket they fit both but you 'really' have to check the
post for the driver's side wiper to make sure it is in the right place
and the sheet metal around it is not not bent. There are a pile of bad
ones on the aftermarket. The result of the poor wiper arm post fit is a
jam and a burn out of the motor or intermittent module smoke out with
bent linkages.

I was given one also when I did my 'glass tub and it was already crapped
out and sheet metaled over that hole to move it. I bought a new one and
got the same crappie fit. I eventually had to cut the hole out of my
old
frame and move it over to the new frame to position it right after a
couple years of messing around with washers and cursing when it died on
the highway in the rain.

Tell him not to forget to ground the windshield frame itself! The
hinges have this nasty tendency to not want to be ground points for the
wipers about half way through bogs as I found out on a trip 1000 miles
from home in a Nova Scotia bog with 3500 miles left to get back
home.... Figured it out pretty quick but getting the rest of the way
through that bog with my head out the door to see was messy....

Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's

Lee Ayrton wrote:
>
> Posting for a friend with a 1984 CJ, 258, std. that he's rebuilding.
>
> What's the spec for cylinder compression? He's getting 160 across all 6
> cyls, which sounds pretty good from here.
>
> He's putting a new fiberglas tub on his Jeep and might have a windshield
> frame from a Wrangler fall into his lap, which was offered to him as
> having a better wiper system than the CJ. Will this fit the tub without
> causing problems with his hard top? I gather that there may be bolt
> hole and vent issues, but since he's putting a new tub on anyway it
> might not matter. Will his existing scratch-and-chip-free windshield
> glass fit the Wrangler frame?
>
> Thanks.

Jeff Strickland

"Lee Ayrton" <layrton@panix.com> wrote in message
news:daa3tf$7l3$1@reader2.panix.com...
>
> Posting for a friend with a 1984 CJ, 258, std. that he's rebuilding.
>
> What's the spec for cylinder compression? He's getting 160 across all 6
> cyls, which sounds pretty good from here.
>

160 is very good. The spec is 150, but the real spec is that they all be
within 10% of each other and that they be within a couple of pounds from one
to the next.





> He's putting a new fiberglas tub on his Jeep and might have a windshield
> frame from a Wrangler fall into his lap, which was offered to him as
> having a better wiper system than the CJ. Will this fit the tub without
> causing problems with his hard top? I gather that there may be bolt
> hole and vent issues, but since he's putting a new tub on anyway it
> might not matter. Will his existing scratch-and-chip-free windshield
> glass fit the Wrangler frame?
>
> Thanks.
>
>
>
>
>
>

Jeff Strickland

"Lee Ayrton" <layrton@panix.com> wrote in message
news:daa3tf$7l3$1@reader2.panix.com...
>
> Posting for a friend with a 1984 CJ, 258, std. that he's rebuilding.
>
> What's the spec for cylinder compression? He's getting 160 across all 6
> cyls, which sounds pretty good from here.
>

160 is very good. The spec is 150, but the real spec is that they all be
within 10% of each other and that they be within a couple of pounds from one
to the next.





> He's putting a new fiberglas tub on his Jeep and might have a windshield
> frame from a Wrangler fall into his lap, which was offered to him as
> having a better wiper system than the CJ. Will this fit the tub without
> causing problems with his hard top? I gather that there may be bolt
> hole and vent issues, but since he's putting a new tub on anyway it
> might not matter. Will his existing scratch-and-chip-free windshield
> glass fit the Wrangler frame?
>
> Thanks.
>
>
>
>
>
>

Jeff Strickland

"Lee Ayrton" <layrton@panix.com> wrote in message
news:daa3tf$7l3$1@reader2.panix.com...
>
> Posting for a friend with a 1984 CJ, 258, std. that he's rebuilding.
>
> What's the spec for cylinder compression? He's getting 160 across all 6
> cyls, which sounds pretty good from here.
>

160 is very good. The spec is 150, but the real spec is that they all be
within 10% of each other and that they be within a couple of pounds from one
to the next.





> He's putting a new fiberglas tub on his Jeep and might have a windshield
> frame from a Wrangler fall into his lap, which was offered to him as
> having a better wiper system than the CJ. Will this fit the tub without
> causing problems with his hard top? I gather that there may be bolt
> hole and vent issues, but since he's putting a new tub on anyway it
> might not matter. Will his existing scratch-and-chip-free windshield
> glass fit the Wrangler frame?
>
> Thanks.
>
>
>
>
>
>