504 plumbing at the oil fill cannister
  • Register
  • Help
Results 1 to 10 of 10
  1. #1
    Fellow Frogger!
    Join Date
    Nov 2010
    Location
    petaluma, ca
    Posts
    136

    Default 504 plumbing at the oil fill cannister

    Here's a puzzling two part question about my '74 GL (US version, XN1 engine). A black plastic cap sits in the oil fill cannister (the place where you pour in the oil) and is held down by two clips. Rubber hose A splits off the output hose of the air filter and connects to the top of the black plastic cap while rubber hose B T's off just below where the hose A connects to the cap and runs to the carburetor. My two questions: 1) what are hose A and B doing, is this part of a pollution control system? and, 2) why does the black plastic cap always have a thin film of oil coating it, wipe it off every time i open the hood, it always returns. The car seems to burn a little oil but I'm beginning to wonder if it's somehow just blowing it out.

    Advertisement

  2. #2
    1000+ Posts robmac's Avatar
    Join Date
    Nov 2004
    Location
    Melbourne / Caulfield
    Posts
    19,211

    Default

    Quote Originally Posted by rpieper View Post
    Here's a puzzling two part question about my '74 GL (US version, XN1 engine). A black plastic cap sits in the oil fill cannister (the place where you pour in the oil) and is held down by two clips. Rubber hose A splits off the output hose of the air filter and connects to the top of the black plastic cap while rubber hose B T's off just below where the hose A connects to the cap and runs to the carburetor. My two questions: 1) what are hose A and B doing, is this part of a pollution control system? and, 2) why does the black plastic cap always have a thin film of oil coating it, wipe it off every time i open the hood, it always returns. The car seems to burn a little oil but I'm beginning to wonder if it's somehow just blowing it out.
    One hose runs to the air filter to draw filtered air into the engine.

    The second hose going to carby should have a one way valve in it (PCV positive crankcase ventilation) valve. This is designed to use the inlet vacuum to maintain the crankcase of the engine at a slight negative pressure.

    The valve should cleaned and ball move freely when the valve is rocked.

    Any generic PCV valve will work satisfactorily as a replacement.

    I'm assuming the pollution system on your car is similar to the OZ cars.
    The less one interacts with rude, ignorant, critical and argumentative members. The more peaceful life becomes.

  3. #3
    Fellow Frogger! Doush_504's Avatar
    Join Date
    Nov 2010
    Location
    Cairo, Egypt
    Posts
    625

    Default

    You mean these ?
    Attached Thumbnails Attached Thumbnails 504 plumbing at the oil fill cannister-img_1668.jpg  
    Chadi

    1982 504 SR white manual sedan with A/C (257 000 Km)
    2012 308 1.6 VTi Vapor Grey manual H/B (35000 Km)
    1994 405 1.6 white manual sedan (208 000 Km)
    1992 605 SV24 (91 000 Km)
    2005 406 2.0L automatic (Replaced with a 2013 C5)
    1983 505 GR white manual sedan with A/C (170000 Km)

    All since new


  4. #4
    Fellow Frogger!
    Join Date
    Nov 2010
    Location
    petaluma, ca
    Posts
    136

    Default

    Doush
    Yes , the setup in the photo looks exactly like what I have with the hose you've identified (arrows, hose B) running from the oil fill into the engine intake manifold (not the carby, my mistake).

    Robmac, you're saying that the airflow diverted from the air filter goes through hose A and more or less into hose B to create a slight negative pressure on the oil in the crankcase, is that more or less right? Jesus, why is this necessary? I dont think I've ever seen another car with anything other than just a screw on cap covering the fill hole.

    But I will check to see if there is a valve in hose B and if the ball moves freely. i do know from memory however that my hose A is kinked and I'm not sure there is very strong air flow through there. What do you suppose would be the consequences if the valve is stuck open (or closed) or if my airflow through the system is weak because of the kinked hose?.

  5. #5
    Fellow Frogger!
    Join Date
    Nov 2010
    Location
    petaluma, ca
    Posts
    136

    Default

    OK, took off hose B, the one that runs from the oil fill canister to the engine intake manifold beneath the carb and that Doush has highlighted with arrows in his post. No evidence of ANY valve in this hose and the hose contained about 1 ml of gasoline, presumably dripped down from the carby? now I'm really confused and a bit worried as its a short trip for this gasoline down the oil fill canister and into the crankcase

  6. #6
    1000+ Posts Wildebeest's Avatar
    Join Date
    Oct 2004
    Location
    Perth Western Australia
    Posts
    2,694

    Default

    rpieper,
    My 504 GL ['79'] has a large hose to the air filter. A smaller diameter hose joined to the big one then leads off to the inlet manifold, no valve in hose, the connection at the manifold has a calibrated hole for vacuum.
    Mine always has a film of oil on the filler cap.
    Have you checked/cleaned the gauze "flame trap" inside the cap and spout?

    Just re-read your latest post. My hose to the manifold attaches the spout on the engine side of the inlet manifold.
    This would make it too high to accumulate any petrol moisture.

  7. #7
    Fellow Frogger!
    Join Date
    Nov 2010
    Location
    petaluma, ca
    Posts
    136

    Default

    thanks for your reply wildebeest. Glad to hear there was no valve in your line and that your fill cap also always has a film of oil on it, every one of these cars seems to be slightly different. I do also see that the small hose running from the fill spout to the intake manifold connects to the manifold at a nipple with a small hole so I guess this is where the vacuum comes from and might be the equivalent of the one way valve robmac mentioned so OK there. I'll have to see if the petrol in this hose was just an accumulation of vapors built up over a long time or a more persistent leak from elsewhere. I dont believe there is any gauze inside the fill cap to clean although there is a mesh support in there, hmm, this might be good place to start esp if the hose accumulates petrol again, thanks much

  8. #8
    1000+ Posts Beano's Avatar
    Join Date
    Mar 2004
    Location
    Brisbane
    Posts
    3,149

    Default

    Quote Originally Posted by rpieper View Post

    Robmac, you're saying that the airflow diverted from the air filter goes through hose A and more or less into hose B to create a slight negative pressure on the oil in the crankcase, is that more or less right? Jesus, why is this necessary? I dont think I've ever seen another car with anything other than just a screw on cap covering the fill hole.
    I think the negative crankcase pressure is because 504s had no crank seal at front or back.....just a slinger...a threaded end on the crank which throws stray oil back into the engine.

    Other cars do have just a screw cap on the oil filler, but plenty have a breather coming from the tappet cover, going to the inlet somewhere. My friend's Toyota Camry engine spat out oil because of this.
    The hole where the hose joins onto inlet manifold is very small .....presumably to restrict suction......but it clogged up with thick gunky oil residue.

  9. #9
    Member
    Join Date
    Nov 2010
    Location
    Hobart
    Posts
    53

    Default

    When I have to 'top up with oil' I find it like being a 16 year old. Preferable to do it at home rather than at the service station. Way too embarrassing. By the time I unclip,the filler cap and drip all over the place, or at least get the funnel from the boot, it is just easier to top up at home. I find that people just don't have the patience, by the time I grab the valve saver, check the oil, top up the windscreen washers, check the water level and the brake fluid. They seem to get really pissed. So now I go to the service station (remembering what a service station was) when it is not busy. And as much, or as little time, that I spend there you will always get some fool who drives in the opposite way to stop the traffic flow!

  10. #10
    Fellow Frogger! callipygous's Avatar
    Join Date
    Jan 2006
    Location
    Toowoomba
    Posts
    798

    Default

    Yes, when service station meant service, not merely a confectionary store that happens to sell fuel. If you're really lucky they might even have a working tyre inflation device.

    My Dad was in NSW recently when he drove past a queue of people waiting for a bowser. Some fella had a go at him saying if you butt in I'll punch you out. So my Dad walked over and calmly asked him what his problem was. He then proceeded to take a bicycle out of the car and pump up the tyres and drove off. His missus in his car was giving him a bit of a rev over that one, my Dad says. Uh NSW...

    Anyway, yes, that crankcase breather is located in the flow of the air to get a vaccum so to evacuate tje crankcase to some degree. Merely fitting it to atmosphere with a filter is enough, but not optimal. All cars have some variation of a crankcase breather, otherwise seals can blow and the rings won't seal as well if pressure builds in the engine.

    A lot of folk who don't want oil vapor getting in their inlet (especiaaly not in their intercooler) fit a catch can. The 504 is good in this area as it has lots of gauze that makes it practically a catch can. Just keep the gauze clean. I've got no idea how well this works compared to catch cans that are marketed, but it does a similar thing!
    Peugeot 504 Intercooled T04 Turbo.

Thread Information

Users Browsing this Thread

There are currently 1 users browsing this thread. (0 members and 1 guests)

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •