i am trying to service my cooling system and want to flush and replace antifreeze. i cant find the drain ****! can someone please tell me where it is and how to get to it. i took off the plastic at the bottom front of car and still don't see it. i have a 1995 bonneville ssei fully loaded. thanks for any help.

It is equally hard to find on my 00 SSEi. I am not sure if it is the same, but maybe this picture will help?

Bottom of the driver side of the radiator, facing back towards the engine.

assuming the 95 SSE and SSEi have the same radiator, J Wikoff is right

I have a 96 SE and I can only see the petcock if I remove the airbox. You might be able to get to it from underneath, but doubtful.

Be thankful you can't find it. It is faster and easier to drain the coolant by removing the lower radiator hose. Those crummy little plastic petcocks break and leak so commonly that I just leave them alone. Just sayin'....

ok, do appriciate it... if i go with the lower hose, will that drain all the antifreeze?

No, but it will drain as much and probably more than the petcock will. Remove the radiator cap to provide a vent before cracking the connection open to drain the coolant. You need a wide pan and you need to carefully wiggle off the hose to (sort of) control the flow of coolant. To keep things under control, you will need to set up a funnel and hose underneath the hose-barb opening and be very careful how you wiggle the hose off at an angle to create an opening at the bottom of the connection. It can be done without spilling anything if you are careful. Another neater option is to buy a piece of 5/16" vinyl tubing about 7 feet long and wiggle it to the very bottom of the side tank of the radiator. Set the outside end of the tubing lower than the end sitting in the bottom of the radiator and give the tube a suck. You can avoid getting any coolant in your mouth by simply watching the clear vinyl hose. Once the siphon has started, place the end in a gallon jug. This will remove most of the coolant. Change the jug if it fills before the siphon breaks.

(This is the method I use when changing thermostats. Drops the coolant level in the engine, keeps the coolant perfectly clean for re-use, and can be done without spilling a drop.)

In your case, it will greatly reduce the volume and the pressure of the coolant remaining in the engine that you can drain from the bottom of the radiator and minimize the chance for making a big mess.

If you want to drain ALL of the coolant, you would need to pull the knock sensors on either side of the engine block. That will drain the remainder of the coolant that can be drained from the block. That leaves the heater core holding some coolant, too. To get that out you would need to disconnect both heater hoses at the tensioner assembly and blow some air gently through the core to force as much coolant as you can get out. This should be done in the direction REVERSE to flow. Normal flow, iirc, is from the top hose on the tensioner assembly to the heater core.

Knock sensors are not easy to remove, are somewhat delicate, must be sealed so that the threads still make electrical contact but will not leak, and are only torqued to about 12 ft-lb.

Unless you have an exceptional problem with deposits that demands it, it is best to leave the knock sensors alone. Most do not try to drain the heater core either. Compressed air can damage the core, causing a leak. And changing a heater core is something you want to avoid if possible.

So, most of us normally will just reverse flush the block and the heater core and the radiator until the water runs clear, then refill with "mixes with any color" coolant using the fill directions here: http://www.bonnevilleclub.com/forum/...=article&k=100

This is normally a summertime job, but if you are in Florida or someplace warm or If you have a heated work space with a floor drain and a water supply and a half a day to kill, you could use this technique to do a really thorough coolant flush:

Here is one way to reverse flush the engine, heater core and radiator separately.

FLUSHING MUST BE DONE WITH A COLD ENGINE TO PREVENT SERIOUS DAMAGE


Engine: Remove the thermostat, then install the top radiator hose and thermostat hose fitting back on the engine with the radiator end of the top hose disconnected. Disconnect the lower radiator hose at the radiator. Wrap a rag around the hose nozzle and flush the engine through the top radiator hose until the water from the lower hose runs clear. Do not run engine. (This reverse flushes the intake manifold, heads, and block.)

Heater core: Remove the hoses from the tensioner assembly and flush through the bottom hose until the water from the top hose runs clear. (This reverse flushes the heater core.)

Radiator: Remove the top and bottom radiator hoses from the thermostat and the water pump. Wrap a rag around the hose nozzle and flush through the bottom radiator hose until the water from the top hose runs clear. (This reverse flushes the radiator side tank and core)

This is then followed with the more typical flush using a flushing tee kit sold by Prestone and widely available for a few dollars.

Running flush: Install a flushing tee in the top heater hose by disconnecting the hose from the top fitting and using a spare piece of hose to connect to the tensioner assembly. Reconnect all but the top radiator hose at the thermostat. Fill the system with water at the thermostat opening and the radiator using the method described in Techinfo. Install a drilled thermostat. With the radiator cap removed, flush through the flushing tee, periodically starting the engine and allowing it to run for only 7-8 seconds at a time. Flushing must be done on a cold engine and the engine must not be allowed to get warm. Cold flushing water will crack hot engine castings. Depending on how cruddy the engine is, it may take 5 or 10 engine "mixes" until the water runs clear after the engine is run.

Final drain and fill: Remove the lower radiator hose from the radiator to drain the water from the radiator and partially from the engine. Remove the flushing tee and both heater hoses from the tensioner assembly and blow the water out of the heater core and hoses by mouth or by gentle air pressure. Reconnect the lower radiator hose. The cooling system holds about 13 quarts, so you will want to add 6.5 quarts of pure coolant to achieve a 50/50mix. Here is one way to do that. Hold the ends of the heater hoses at the same level and pour straight "mixes with any color" coolant in one hose until it begins to run out the other. Reconnect the heater hoses. Fill the engine at the thermostat opening, and radiator as described in Techinfo but use straight coolant until you have added a total of 6.0 quarts to the cooling system. Top up the radiator with pure water. After cleaning it, fill the expansion tank with .5 quart of pure coolant followed with pure water.

There are drain plugs in the block as well. Kinda hard to reach, though. Below the center exhaust runner on each side.

vdawg4, please disregard my knock sensor comment above. It is applicable to Series II engines. I did not recall when writing my reply that in 95 the SSEi was still a Series I engine.