COOLANT DRAIN TAP

haydn callow · Post by **haydn callow** » Thu May 24, 2007 9:19 pm

I know there is a coolant drain on the bottom of the radiator, drivers side. Is there another one on a different part of the engine? If there is, please point me in the right direction.

Peg leg Pete · Post by **Peg leg Pete** » Thu May 24, 2007 9:20 pm

Haydn the driver side drains all the coolant out, why do you need a second one?

haydn callow · Post by **haydn callow** » Thu May 24, 2007 10:01 pm

Peter, It's reguarding the tests we are doing with the coolant loss alarm.
We want to drain the hot, under pressure running engine to simulate as many scenariors as possibble. Draining with the rad drain under these conditiond has thrown up some strange results and we want to explore further. Opening the rad drain has the effect of a top hose leak and we would if another tap is located in the right place, like simulate a bottom hose leak.
The Bongo does not always do what you might expect. I have heard that there is another tap but Don't know where to look.
By the way has anyone heard of a "suckback valve" in a rad cap and does the Bongo have one.
Another point, I now have 6 different Rad caps , all off Bongos and all with the same label on. I expect there are more out there.

dandywarhol · Post by **dandywarhol** » Thu May 24, 2007 11:13 pm

haydn, the "suckback" valve will be the light vacuum valve on the bottom of the cap - you can easily pull it open between your fingers. It's there to allow air/water (depending on the system) to re-enter the header tank when the system cools down, otherwise the hoses would collapse. all caps have some soet of vacuum valve.

Interesting to see 100% of the replies on my "cap type" poll is yellow header tank and red on the radiator. I worked on a 17,000 mile Bongo the other day and it was that configuration too............

Dannyboy · Post by **Dannyboy** » Thu May 24, 2007 11:34 pm

Hi Haydn,

There is another drain for the coolant. It is on the long pipe that runs from the front of the engine, forward, then down, then forward, then back up to the top radiator hose. As this is higher at the ends than in the middle it does not drain when the drain tap on the radiator is opened.

If I remember correctly, it was in the form of a rubber cap which pushed over a narrow bore tube and was held in place by a spring clip.

All the best.

haydn callow · Post by **haydn callow** » Fri May 25, 2007 6:44 am

Dandywarhol.... Are you saying ALL pressure caps have a suckback valve of one sort or another? I dismantled a cap the other day, there was no valve looking at it but inside there was a small solid rivet shaped bit of metal and a spring. Could this have been a valve ? We were trying to find out why there is no electrical continuity between the top and bottom of a pressure cap.
Dannyboy.....Can you guide me a bit closer to this 2nd drain ? what is it close to, which side, access from under or above? Thanks both of you

haydn callow · Post by **haydn callow** » Fri May 25, 2007 11:46 am

Peter...are you saying the radiator drain tap will empty the whole system?? What about the bottom hose if the stat is shut??heaters etc??top hose??
Funny thing these Bongos

dandywarhol · Post by **dandywarhol** » Fri May 25, 2007 4:47 pm

All systems have to have a form of vacuum valve otherwise the hoses will suck in and collapse when the coolant cools down

Vanmanerik · Post by **Vanmanerik** » Fri May 25, 2007 8:43 pm

Haydn, drain 'tap' on top hose to radiator.

Goto http://www.lushprojects.com/bongoparts/ ... 02).html#1

Or copy the link and paste it into your browser -

and look at 13-104T.

Hope this helps with testing the low water warning device.

haydn callow · Post by **haydn callow** » Fri May 25, 2007 9:07 pm

Vanmanerik.... You are a DIAMOND GEEZER.. got it!!

COOLANT DRAIN TAP

COOLANT DRAIN TAP

Top hose drain device.