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Thread: Cooling system pressure testing.

  1. #1
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    Cooling system pressure testing.

    Guess how im spending nye.

    Anyway, i cobbled together enough bits to pressure test the cooling system of the green shitheap. I have some questions.

    The cap rating is the beginning of pressure relief presumably with full open at some indeterminate point but the chingling cap with the chingling radiator that should open at 13psi, Isn't.

    Thats a problem i can fix by testing a bunch of tridon caps until i find one that does its job but whats the deal with opening point on caps?

    Second issue. Is there a protocol for how long pressure should hold? Ive dropped 2psi in 1.5 hrs with 15psi input.

    I figure a supposedly sealed system should hold pressure indefinitely, is that a correct assumption?

    I cant discount leaks from my crappy test rig so ill test the hose etc separately.

    Help me out, other pf cunts with no life.
    Last edited by chartreusehj; 31-12-16 at 04:31 PM.

  2. #2
    Purist, whats that? Jason Broadhurst's Avatar
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    The cap would be + or - 10 kPa at best.

    I would soapy water test each fitting when at 100 kPa.
    Jason Broadhurst

    Someone once asked me if they could use my mower. I said "sure, so long as it doesn't leave my yard"

  3. #3
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    Cap has closed completely and I'm nowhere its 13psi rating, even allowing for tolerance its not even within 15% at the moment but its probably not a big deal except I've seen it.

    Reason for my shenanigans is I had a bit of a mixed race marriage between water and oil, I've replaced inlet manifold gaskets and properly goo'd around all ports/water passages (water crossover was stained around the gasket and there was a little water in the valley) but with cometic head gaskets I'm really not happy about the prospect of pulling the heads if they are leaking and it seems its a common issue.
    Last edited by chartreusehj; 31-12-16 at 05:40 PM.
    Quote Originally Posted by Dogsballs View Post
    I'd rather put a 253 than efi

  4. #4
    Goat roper Motherfucker Jones's Avatar
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    So are you testing with the cap on or through the cap hole?
    Quote Originally Posted by RVK 355 View Post
    Hold it flat cunt

  5. #5
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    Quote Originally Posted by Motherfucker Jones View Post
    So are you testing with the cap on or through the cap hole?
    Cap is on, everything is as normal except I removed and tapped the water pump through the crossover to pump line. I'll upload a dodgy pic.
    Quote Originally Posted by Dogsballs View Post
    I'd rather put a 253 than efi

  6. #6
    Goat roper Motherfucker Jones's Avatar
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    You're better off testing through the filler neck with the cap off. You'll get more pressure into it and have more chance of finding a leak.

    Also if there's any heat in th system you'll lose pressure as it cools off
    Quote Originally Posted by RVK 355 View Post
    Hold it flat cunt

  7. #7
    Goat roper Motherfucker Jones's Avatar
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    Not a leaky head bolt/stud?
    Quote Originally Posted by RVK 355 View Post
    Hold it flat cunt

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    Click image for larger version. 

Name:	Dodgy_pressuretester.jpg 
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ID:	97096

    Here tis.

    Normally there is a bypass line from the thermostat to the water pump to circulate water while thermostat is closed.
    Quote Originally Posted by Dogsballs View Post
    I'd rather put a 253 than efi

  9. #9
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    It seems to be holding at 12.5 psi but I've been looking after 4 kids while drinking and the clear hose is held on with hopes and dream and a cable tie.
    Last edited by chartreusehj; 31-12-16 at 08:22 PM.
    Quote Originally Posted by Dogsballs View Post
    I'd rather put a 253 than efi

  10. #10
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    Pressure test through the filler. It should hold pressure with a 1 psi change over an hour by the books but all pumps are usually 2 psi due to the pump.

  11. #11
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    Also cold testing can bring up leaks that weren't there when it's hot I usually go 15 psi cold though

  12. #12
    Registered User dnegative's Avatar
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    If you have sealed the manifold and there is nothing else where things can leak and mix your going to be pulling the heads

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    Quote Originally Posted by dnegative View Post
    If you have sealed the manifold and there is nothing else where things can leak and mix your going to be pulling the heads
    This is not what I want to hear.
    Quote Originally Posted by Dogsballs View Post
    I'd rather put a 253 than efi

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    Quote Originally Posted by Rdyno View Post
    Pressure test through the filler. It should hold pressure with a 1 psi change over an hour by the books but all pumps are usually 2 psi due to the pump.
    I'll post pressure drops tomorrow but there is still 12psi in it.
    Quote Originally Posted by Dogsballs View Post
    I'd rather put a 253 than efi

  15. #15
    Down with ma homies Greg Rust's Avatar
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    Pull plugs and look in each zoolander for water.
    xw Falcon 393 full race cam, NGK spark plugs.

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    Quote Originally Posted by Greg Rust View Post
    Pull plugs and look in each zoolander for water.
    No water.
    Quote Originally Posted by Dogsballs View Post
    I'd rather put a 253 than efi

  17. #17
    Goat roper Motherfucker Jones's Avatar
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    These leak at the front cover too from the water ports into the timing chain area. Cover just corrodes away and stops sealing. Or like I said the head bolts/studs are open into the water jackets. What did you use to seal them? Pull the rockers covers and you might see some water around a bolt

    Are you getting water in the oil or oil in the cooling system?
    Quote Originally Posted by RVK 355 View Post
    Hold it flat cunt

  18. #18
    Goat roper Motherfucker Jones's Avatar
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    It could even be condensation from occasional starts without enough drive time to cook the moisture out of the engine.

    Is it a 355? Did you clearance the bottom of the bores?
    Quote Originally Posted by RVK 355 View Post
    Hold it flat cunt

  19. #19
    Down with ma homies Greg Rust's Avatar
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    Got any photos of the deck and cylinder head face? MLS gaskets need a fine surface finish as they don't compress like CNAF standard gaskets to take up the surface finish irregularities.
    xw Falcon 393 full race cam, NGK spark plugs.

  20. #20
    Hungry Hungry Hippo Tripper's Avatar
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    Quote Originally Posted by Motherfucker Jones View Post

    Are you getting water in the oil or oil in the cooling system?

    This is what we need to know. Since its a fresh build. A slight oily film in the coolant is not much to worry about as it could be coming from any coating applied to machined services. Would drop and change it a few times before worrying about it much
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  21. #21
    sack riding 10sec rx7's Avatar
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    Did you put the head gaskets on dry? If so that's your problem
    im a cunt
    and apparently i dont know shit...

  22. #22
    Goat roper Motherfucker Jones's Avatar
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    I've used mls gaskets dry plenty of times and not had an problem. I'm not sure I'd bet on that 100%
    Quote Originally Posted by RVK 355 View Post
    Hold it flat cunt

  23. #23
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    If you didn't put the Holden goop on the studs it will be leaking there

  24. #24
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    All the studs got white 3bond, head gaskets were split and copper coated.

    Timing case is good, same block ive owned for 20years.

    Block and head wont be anywhere near 50RA and it wasn't ground this time, just checked for square but the guy who machined it said it would be ok and he's done hundreds of holdens (Cable & Burns for those old enough to remember the glory days of melbournes drag scene)

    The inlet manifold gasket went on dry because im an idiot, I think now the leak was from the water port and there was staining all the way to the inner edge plus a small amount of water sitting in the valley, dipstick was milky, the new gasket set got painted with gasket sealant.

    Its still holding 10psi from yesterday and theres nothing in the clean pan I sat under the sump after I dropped the oil. The oil doesnt look too bad, 2psi drop in 12 hrs probably means its going to be ok.

    The water was in the oil, there was nothing in the cooling system. I got suspicious because I was losing water and couldnt figure out where it was going, if it was on the ground I probably wouldnt give a shit but not finding it was a problem.
    Quote Originally Posted by Dogsballs View Post
    I'd rather put a 253 than efi

  25. #25
    Down with ma homies Greg Rust's Avatar
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    I had no problems using Cometic MLS gaskets installed dry on the Clevo but did get a good Ra surface finish
    Last edited by Greg Rust; 01-01-17 at 12:31 PM.
    xw Falcon 393 full race cam, NGK spark plugs.

  26. #26
    Goat roper Motherfucker Jones's Avatar
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    The only way you can get water to oil from the head gasket would be into the valley on a free oh. There's a good chance it's just condensation

    Is it a 355? Did you clearance the bottom of the bores for the rod bolts? Sometimes you can hit water there.

    Only other thing would be get some temp into it and pressure test. You'll get a pressure drop but it might be something that opens up with heat. You might see a trail somewhere. Doesn't sound like a major issue either way. Skiditfaggot!!
    Quote Originally Posted by RVK 355 View Post
    Hold it flat cunt

  27. #27
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    Water can slowly seep past the rings. Yea heat can seal things up or it can act in reverse depending on where the leak is.

  28. #28
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    Its a 355 but was clearanced 15 years ago and has never leaked before. I got bored of watching the pressure not dropping and released it at 9.5psi about an hour ago. Only other thing is maybe something opening up with heat but im pretty confident it was just my rushed inlet manifold install.

    Might adjust the test rig and do it hot.

    I'll put some oil in it and give it a hiding.

    Thanks fellas!
    Last edited by chartreusehj; 01-01-17 at 04:59 PM.
    Quote Originally Posted by Dogsballs View Post
    I'd rather put a 253 than efi

  29. #29
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    Quote Originally Posted by Rdyno View Post
    Water can slowly seep past the rings. Yea heat can seal things up or it can act in reverse depending on where the leak is.
    Why is there water in the bores ?
    ......................

  30. #30
    Registered User gtrboyy's Avatar
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    We used to do pressure test through filler neck...pump up to 15,check no visible leaks then come back 10mins later check again.

    Curious if you get pressure drop on holden v8 if no heater bypass could still be airlocks not bled out?

    Wouldn't be surprised if condensation in oil..check catchcan probably more water than oil in there too

    Have had 2 radiators in vy ss ute that would occasionally lose water after a drive...turned out small crack would open up with heat & pressure

    If paranoid last resort try that tee-kay combustion tester stuff
    Last edited by gtrboyy; 01-01-17 at 05:48 PM.
    an easy fix is get a mate to drive in front of you at 60 then 80 then 100 and mark in on your speedo with some liquid paper.

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