Help ! I have a coolant leak !

[Ben]

I have sprung a leak !

I came out the other day, having extolled the reliability of my car to all and sunder, and spotted a pool of water underneath. I laughed it off "it couldn'nt be mine" and drove off. Luckily my subconcious ( BIG BROTHER) took over and after about 30 seconds I felt guilty about not checking it, so I switched off !

It was mine !

I topped up ............about a litre and drove the short distance home where it continued to drip !

I looked all around the front end and decided since I couldn't see the scource I would need to do some stripping.

Having removed the battery, dropped the rad, moved the alt, the air filter housing and finally the fan, water pump and thermostat housing, all during my lunch break at work.........I couldn't see a definite trace of a leak !

I examine all hoses, there were decent, no pinholes I replaced the gaskests for the pump, the pump housing and the thermostat housing I recalled that when I rebuilt the engine I had a problem with the thermostat by-pass pipe banjo bolt. The upper one went in fine but the lower one broke. I got a new one and drilled out the old one then picked out the remainder of the threads. It looked okay and wnet together well. I gingerly "nipped" it up, feeling that it might pull if I went any tighter.

Well its two and a half years down the line and this is the first sign of trouble !

I cant quite see the source of the leak but I need to strip the area again and I'm going to have to disturb this bolt. For a better repair I was going to fill the hole with JB Weld or similar, then drill and tap it again !

Has anyone with more experience done this before or could you suggest any better method ?

Finally since my memory is hazy, I just cant recall the exact layout here. Does the lower banjo bolt go through the inner pumpn housing and thread into the block ? How does it seal against the pump housing? Should there be "crush washers" on either side of the by-pass pipe ? I appear to only have the pipe sitting against the head (on the higher on) and the alloy pump housing (on the lower one)

Any ideas where my leak suddenly came from ?  

I'm supposed to be travelling with the Mercedes Club on Sunday !!

HELP    :?

Regards,
Ben in Ireland.
'64 230SL 4sp.

[J. Huber]

Hi Ben. Sorry to hear of your travails. I cannot really help much except to say that when mine developed a leak, it was a seam near the bottom "trough?"... The leak was fairly slow -- but constant. Somebody recommended that leak stop stuff -- BUT -- upon the recommendation of my mechanic and our trusty experts on P113, I instead took it to a repair shop. In my case, we discovered that the radiator was past its prime -- so I decided to go with the high-efficiency version....It has worked flawlessly.

James
63 230SL

[Douglas]

The best way to tell where the leak is is to put the system under pressure using a pump. (It's basically a bicycle tire pump with a fitting for the top of the expansion tank and a release valve.)

Leaks generally make themselves pretty clear once everything is under pressure.

Douglas Kim
New York, NY
280 SL #016220

[ted280sl]

Ben,
  I have used the anti-leak metalic additive in many cars including my pagoda. It has worked for me in the past especially for minor radiator leaks. I believe the cost is less than $2 US and it may solve your problem. If it does not work you can always strip the front end.
Ted
PS: I replaced my radiator core and it started to leak a few year later. I added some anti-leak additive and it has not leaked in two years.

[Ben]

Well the problem is that the leak is NOT from the radiator. It leaks without even putting it under pressure. The problem is that I cant see the source without stripping off the rad at least, and then the coolant has dropped to a level that it doesn't leak out any more [!]

Its an irregular leak too, this morning there was about 1.5 litres on the garage floor, whilst yeasterday all day only a cup full !

I reckon its definitely from the pump housing area since this is the highest placve I can see it. The ahead gasket appeared dry the other day when I had everything out !

Again I ask if someone can enlighten me  

quote:Does the lower banjo bolt go through the inner pumpn housing and thread into the block ? How does it seal against the pump housing? Should there be "crush washers" on either side of the by-pass pipe ? I appear to only have the pipe sitting against the head (on the higher on) and the alloy pump housing (on the lower one)

Thanks !

Regards,
Ben in Ireland.
'64 230SL 4sp.

[Naj ✝︎]

Ben,
Does this picture help at all?

Download Attachment: DSCN0285_edited.JPG
38.85 KB

The heater and rad hoses go on the w/p rear housing. The banjo bolt goes on the t/stat housing with sealing washers either side.

naj

65 230SL
68 280SL

[Ben]

Thanks Naj,
   Unfortunately the picture doesn't really help as I have it stripped to that level but I havent removed the bolt again yet for fear !

However if you state there should be a washer, it seems likely to me, on each side of the fitting then I think I may have missed one upon reassembley and hence have a new leak, despite fixing the original one !!

Do you know what the arrangement between the hgousing and the block is ? If the banjo bolt goes into the housing, arte the threads in the housing...........the more I think about it the more I have confused myself...........a little more stripping is required here I think !

Regards,
Ben in Ireland.
'64 230SL 4sp.

[Naj ✝︎]

Ben,
Have a look around the water pump. (Did you renew it when you rebuilt the engine?)
There are 2 or 3 holes in the main housing body. If the seals inside are worn, water will leak out of one of thse holes.

Download Attachment: TstatHsg007.JPG
28.2 KB

naj

[Ben]

Thanks Naj !

I have it stripped out and its sitting in my hand now  !

It seems my memory is even worse than I thought !

The by-pass pipe upper fitting is screwed into the head and the lower one is threaded into the pump housing. There should be small crush washers on either side of the fitment, and mine has them. The leak is not from here !

It looks like I have a regular leak from the housing to block gasket, though since the coolant was only changed a few months back it is clean and there is no stain. Also upon removal everything dries up so I can't be positive. At least the head gasket is intact as it is bone dry !  

I have ordered 4 washers, the housing to block gasket, the pump to housing gasket and the 'stat housing gasket !

Should sort it !

Funny thing...........I rang Mervyn at Jacksons and they had just had a power failure, everything was off, but he appreciated my predicament and went off with his torch in the dark as he was sure he had them in stock ! He rang back 20 minutes later to say he found everything, he had the part numbers and locations off the top of his head, and they were being sent immediately !

"What about payment? " ......I said !

Ahh we'll sort it out at a later date !!

Now thats what I call FIRST CLASS SERVICE !!  

Regards,
Ben in Ireland.
'64 230SL 4sp.

[rwmastel]

quote:Originally posted by Ben

I rang Mervyn at Jacksons ..... Now thats what I call FIRST CLASS SERVICE !!

I don't see Jackson's in our database.
http://www.sl113.org/data/show_table.asp?table_name=usr_parts_and_service_suppliers

Rodd
Powell, Ohio, USA
1966 230SL, Euro, Auto, Leather, both  tops
1994 E420

[Naj ✝︎]

quote:I don't see Jackson's in our database

done

naj

65 230SL
68 280SL

[hands_aus]

Hey Ben,
The water pump (impeller part) has leak holes that allow water to escape if the seals give out.

It happened to my cay about 18 months ago. I had driven to a business and was standing buying something and looking out at the car and there to my horror was this ever increasing pool of green coolant. It was pouring out that hole.

A flat top took me and the car home.

A new pump impeller and everything was sorted.

Question...
The small metal pipe you are referring to.... Is it for water? I thought it was an oil line.

I replaced the thermostat last Saturday and the hollow bolt needed two washers (now copper not aluminium), one each side of the banjo fitting.

Bob Smith (Brisbane,Australia)
RHD,1967 early 250 SL, auto

[Ben]

Ahhh Bob.......I take it from your comment that you have a Haynes manual ?

The Haynes actually calls this little fitting a " chain tensioner supply line "  !!

No it is a water line and as you state there should be 4 washers total there, although when I got mine 2 years ago they were alloy ! I havent recieved the new ones yet............damn Irish carrier pidgeons dont do any work when it rains !

Anyways yeah I know about the leak holes, most pumps have them, but you can see then whilst the engine is running and mine were definitely not leaking there !

In fact I discovered the leak only a few minutes ago !

Would you believe its a porous casting !!  There is a pin hole, literally so small I though it was a speck of dirt on the back of the casting. I poked at it and it opened up to reveal a small hole ! It all makes sense now. It may have corroded from the inside over the years, my coolant was always fresh. Anyway for now I am repairing it with chemical metal putty.............I'll update when its back together but if anyone ever has this housing off .........
examine it very closely, particularly just above the blockn fitting area !!

Regards,
Ben in Ireland.
'64 230SL 4sp.

[hands_aus]

quote:Originally posted by Ben

Ahhh Bob.......I take it from your comment that you have a Haynes manual ?

I do have the Haynes as well as both the service manuals.

BTW what does the little by-pass pipe by-pass?

Glad you sorted the leak... nothing like not being able to find the cause of a problem.

Bob Smith (Brisbane,Australia)
RHD,1967 early 250 SL, auto