I have a 96 c280 and on the way to work this morning the low coolant level warning light came on. I started getting worried when I noticed the temp gauge approaching 100C. When I arrived at work, I tried to see where the leak was coming from. I've attached some pics. I noticed that the coolant seemed to be coming from underneath the water pump. From what I could see the hoses looked fine. I'm wondering if the leak is originating from the water pump, does the entire pump need to be replaced or is there a gasket/o-ring that might be the culprit. Also, what is the difficulty level in replacing the pump/gasket/o-ring myself. Also, if needed, should I buy a new pump or refurbished pumps available and can you suggest a supplier.

The first pic doesn't show much except the orienation of the camera to the pump. In the second pic you can see the actual pooling of the coolant under the water pump.

Thanks!
Jason

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seems from the hose. retight the clamps.

if you will go to a reasonable workshop, they will pressurize your cooling system to 1.5bar and you will clearly see the source of leak.

 

Yeah, I guess I should have mentioned that the stains near the hoses on top of the water pump were there before I bought the car. It's definitely not coming from the hoses on top.

 

I'm stilll new to this forum so hopefully this will reply to you directly. The stains on the top of the water pump were there when I bought the car. I'm pretty sure that the leak is not coming from the hoses connected to the top of the water pump. I'm going to fill up the reservoir again and see if I can detect the leak. If I can confirm that it isn't coming from any hoses connected to the water pump. What do you think the most likey problem is? If it looks to me that the leak is coming from the water pump do you think that I will need a new water pump or just an O-RING? Or something else?

 

Just a suggestion......... if the reservoir was full and you noticed coolant was at high temp
you probably would be able to do visual check or verify where pressure or coolant coming out.

Just be carefull if you're not comfortable on it do not do it.......

I did have coolant issue last week.....and visual inspection while problem was present helped me ruled out some possibilities.

Sleepwalker could this be the case you have sited? Pressure loss from broken head gasket.
Goodluck........

 

Thanks for the suggestion. The leak is so bad that it doesn't even require the car to be on to leak. In the close up pic in previous post where the coolant was pooling up I just noticed that I could see where droplets were hitting the front edge of where the coolant was pooling. refer to pic. I think the leak is coming from where the pulley attaches to the water pump. Does this mean that the water pump needs to be replaced or is there a gasket/o-ring that might be worn out.

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Well, I got a small mirror out and it looks like the drip is coming from a small screw on the bottom of the water pump. I'm not sure if it's a screw or something else but the water is definitely dripping off of it. It may be because it is the lowest spot on the water pump but it may just be leaking from there. Any suggestions at this point. Thanks

 

this is just a leak and no complaints of excessive temperature. a matter of locating the source.

 

okay, so it might be the sealing on the water pump which usually leak in time.

you got two options. if you remove the belt and there is a movement on the pulley, replace the pump. if not, a sealing kit is available.

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replacing the water pump is much much easier than repairing it.

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