Announcement

Collapse
No announcement yet.

late 70's early 80's BMW coolant expansion bottle question

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

  • late 70's early 80's BMW coolant expansion bottle question

    hey all, so I have a question about the pill shaped coolant bottles in this range of BMWs.

    I have an engine swap going on ( 06 Subaru EZ30r into an 85 Vanagon) and need a better coolant expansion bottle

    I was wondering how the cap works on these bottles. are they prone to failure. ? I also wonder if the bottle is prone to failure or leaking at the neck ?

    I see there is a small pipe on the side of the filler neck, is this to vent coolant and suck in coolant as it expands and cools ? if so then there is a pressure valve in the cap that lets coolant in and out ?

    maybe I should mention what I'm doing...
    so in a VW vanagon the bottle has a cap with a valve and pipe on it. as far as I understand, the valve opens at pressure and vents excess coolant to a overflow tank. then when the engine cools and the coolant 'shrinks' down the vacuum draws coolant back from the same overflow bottle.

    the problem I have is, the caps are all crap Chinese made and either bad right out of the box, or just fail early. the other small problem is the bottle itself is an ugly blob of a shape.

    the thing I like about it is it's translucent plastic so you can easily see the bubbles come out as you bleed your system, and then also see at a glance if the expansion tank is low (but not low enough to flash the idiot light)

    the vanagon coolant system is big with alot of places for hose clamps and possible weeping. so I'm trying to build it better...I haven't ever built or designed a coolant system before. what I've built so far works, it's my daily driver. but bit by bit I'm re building things better as I re evaluate and drive it.

    this is the bottle I'm looking at. I'm hoping the BMW sensor will work with the vanagon idiot light too...just a 2 wire connection on the van.


    I'm open to other suggestions, but I prefer a bottle I can see through, with a level sensor on top
    something that's not oddly shaped making it hard to mount or look out of place.
    something not difficult to get parts for.
    I'm not familiar with how other coolant bottles, caps and overflow tanks systems function so it's kinda hard to figure what work out ok.

    thanks for any help/suggestions

  • #2
    I've never had any issues with mine other than the thread on the sensor hole getting stripped out, but that wasn't my fault. So I'd recommend doing it. And the BMW sensor is two prong too so I wonder if it would work


    1983 528e, 230,xxx miles, Alpine weiss. M20B25 swapped
    my tumblr.
    What the f**k is a build thread?

    Comment

    Working...
    X