l2111 Posted November 2, 2005 Share Posted November 2, 2005 --------------------------------------------------------------------------------I have a 57 Buick Roadmaster series 75 that i just replaced the thermostat and had the radiator re-cored but the temperature is reading HOT. After about 10 min the upper radiator hose begins to heat up but the radiator remains cold to the touch. I know that all I have left is the water pump and temperature sending unit. I guess my question is how I check the sending unit and/or water pump. Any advice is helpful and appreciated, thanks in advance. Link to comment Share on other sites More sharing options...
Roadhog Posted November 2, 2005 Share Posted November 2, 2005 Leon, the first thing is to make sure you didn't install the thermostat up side down, I did that once! Next check all hoses passages etc for a blockage? Next,with the therm. out and coolant up to the housing start engine. coolant should FLOW out of top (where therm. sits) If it doesnt pull the water pump I suspect the impeller has come loose on the shaft, they are pressed on. There is actually no easy way to check the guage. It is not electric but is a unit consisting of a pressure gauge connected by a capillary tube to a vapor bulb. The heat of the coolant causes the liquid in the sealed vapor bulb to expand and exert pressure on the gauge hence moving the needle. I guess you could remove bulb (from left head) in stick it in a heated liguid say about 180 deg. and gauge should read in the normal range? I really don't think the gauge is the problem though! GOOD LUCK! Link to comment Share on other sites More sharing options...
l2111 Posted November 2, 2005 Author Share Posted November 2, 2005 If it is the impeller I assume I would need a new water pump?(not knowing what is an impeller) I know the radiator hoses are new and checked the thermostat to make sure by any chance that i didnt put it in upside down. I know I couldn't find a water pump for this car but I did find someone to rebuild it.(oldbuickparts.com) do any one know of any othe place that does that or has new ones? Link to comment Share on other sites More sharing options...
l2111 Posted November 2, 2005 Author Share Posted November 2, 2005 also my tail light work but not my brake light, besides the stop light switch what am I missing. I have no clue about the wiring but i did find a connector right by the master cylinder that is not plug to anything and don't know where it belongs. Link to comment Share on other sites More sharing options...
Guest imported_JPIndusi Posted November 3, 2005 Share Posted November 3, 2005 I haven't worked on these year cars in a long time. However, I have replaced thermostats and done other things with cooling systems on older Buicks and newer cars. My experience is that you need to be sure that the system is not airbound and the water in the block is reaching the thermostat pellet. Try to locate a heater hose near the base of the thermostat housing, loosen the clamp and pull back the hose until you bleed off the air and have coolant starting to flow out of the hose nipple. This will assure that hot coolant is reaching the thermostat and going into the top of the radiator after the thermostat opens. I also have had new thermnostats either fail to open or stay open.Just my $.02 before you condemn the water pump.Joe, BCA 33493 Link to comment Share on other sites More sharing options...
The Old Guy Posted November 3, 2005 Share Posted November 3, 2005 The connector by the master cylinder is supposed to hook to a hydraulic switch ,which completes the circuit to the stop lights. Take a piece of wire ,and short across the two terminals in the connector. If the stop lights work, you need a hydraulic switch screwed into the master cylinder. Link to comment Share on other sites More sharing options...
l2111 Posted November 3, 2005 Author Share Posted November 3, 2005 Thanks alot everyone. I'm going to try all these things this weekend if the weather permits. Hopefully it will take care of these problems. I will post back next week if completed. Link to comment Share on other sites More sharing options...
l2111 Posted November 6, 2005 Author Share Posted November 6, 2005 Well, I got the stop lights to work thanks to The Old Guy. I bled the heater hose, still the same after that but then I looked in the service manual and found a section about the exhaust manifold valve. It says if stuck in the closed position it will cause overheating. Since this car has been sitting up for some time I think this will solve my problem. (I hope) Next weekend I will try to see if that is it. I'll probably change the thermostat for the second time just to be safe. Be back soon. Link to comment Share on other sites More sharing options...
l2111 Posted November 12, 2005 Author Share Posted November 12, 2005 Well, well. I tried moving what I think is the heat riser to open the exhaust, Which was on the other side of the spring itself. I didn't see the spring move nor do I know if its suppose to. I guess now I will take off the exhaust pipe to actually look inside of the manifold. I don't know if its opening or not. This is really bothering me. I want to say its a bad gauge but to afraid i will harm the motor. I'am not sure how to test the gauge. Boy do I need a drink. Link to comment Share on other sites More sharing options...
JohnD1956 Posted November 13, 2005 Share Posted November 13, 2005 The heat riser valve either rotates or it doesn't. You might not see the spring move because only the center of it will show any movement when the valve is opened and closed. While the engine is cold, you should be able to freely move that valve a 1/4 turn by hand. If you can't, you should spray some PB blaster on boths sides where the rod goes through the manifold then gently tap the valve handle ( that piece you saw on the other side of the manifold from the spring.)If you are going to test the guage the best way is to put on a temporary manual guage. Look at your heads to see which end of the motor the original temp guage is hooked to. On my 56 it is hooked to the drivers side head, towards the back of the engine ( side by the firewall, not the side by the fan) Once you find the hook up point look at the other head directly opposite that connection. You may see what appears to be a slotted screw in the other head in the same location. That would be the best place to hook up your temporary guage. And that way you can compare both guages at the same time to actually see what the numbers are for the corresponding position on your factory guage. Meanwhile, I would not try to disconnect the factory guage at the engine. The part inside the head has a tendency to get stuck in the hole and then the slim tube breaks off when trying to unscrew the fittings. Then you will need the guage and tube professionally repaired or the entire guage replaced. That tube is an integral part of the guage. As to that slotted screw, this is no place to use incorrect tools. I know Sears has a socket for 1/2 in drive that forms a slotted head. This socket has a thick slotted design that fits that screw tightly. The tighter this fit , and the more leverage, the better your chances of getting that port open with no damage. I am sure other tool makers have such tools too. As a matter of fact I have a snap-on catalog right here. I see the perfect tool on page 125. It's called the "Flat tip" Socket and comes in three sizes:7/16 x.050" part # SW28E1/2 x .075" SW32E5/8 x .093" SW40EThese would be much preferred over an ordinary screwdriver because you can put it in on a square angle approach, hold it straight and have maximum leverage to get that old screw out of there.Good LuckJD Link to comment Share on other sites More sharing options...
l2111 Posted November 13, 2005 Author Share Posted November 13, 2005 Thanks JD, I couldn't tell if the flange was turning so I unhooked the manifold from the exhaust pipe to see it clearly. I can turn the counter weight but it does not turn the stem and flange inside. I tried carb cleaner and PB blaster and still no luck to turn it. This was with the car not running. I figured that if I turned the counter weight everything else would move with it. Maybe I'm wrong. I guess I will continue to put PB on it until it soaks in. Link to comment Share on other sites More sharing options...
JohnD1956 Posted November 15, 2005 Share Posted November 15, 2005 Now you have me wondering about my 56. I'll be into that this weekend.Is your valve ( inside) open or closed? If it is open I would not try to free it up. Leave it alone. I've heard it said here that the heat riser only comes into play in colder driving weather. Some people remove the guts to open them and leave them open full time. Unless of course, you plan to drive it this winter... Link to comment Share on other sites More sharing options...
42crazy Posted November 16, 2005 Share Posted November 16, 2005 Leon, if you want to find out where heat is generating, or not, invest in an Infrared Hand held temperature gun. I bought one a couple of years ago when my '65 Wildcat seemed to be overheating, but proved with the gun that it was an over-sensitive sending unit. The red lite would come on as soon as I shut the ignition off. When I checked on the input side of the radiator, and then the exit side, I found that everything was okay, was not overheating. It costs about $100 at your local parts store. It can be used for all sorts of things, checking temp of tires, bearings, which cylinder is dead or not, its really an invaluable tool. Paul Link to comment Share on other sites More sharing options...
l2111 Posted November 17, 2005 Author Share Posted November 17, 2005 The heat riser is open about 25% I'm planning on taking it out this weekend.(I HOPE) If that doesn't work then i'll buy the tempature gauge to read the temp. Link to comment Share on other sites More sharing options...
l2111 Posted November 20, 2005 Author Share Posted November 20, 2005 Well, I got the flange out today. I couldn't check because it would not stay running(oh boy). I think my fuel pump stop working. I changed the fuel filter and put everything back together and it would not start. I noticed there was no gas in the filter glass so I unhooked the side that reads IN just to see if anything would come out and there was nothing. I even tried to start it while it was off and nothing. Does anyone have some advice for me before I shoot the darn thing. Link to comment Share on other sites More sharing options...
JohnD1956 Posted November 20, 2005 Share Posted November 20, 2005 May sound totally stupid, but make sure you have gas in the tank. My 56 would run out every year on me at least once because of erratic fuel guage. Happily I can now say that is fixed.JD Link to comment Share on other sites More sharing options...
l2111 Posted November 20, 2005 Author Share Posted November 20, 2005 I was thinking that also and I hope you are right... Link to comment Share on other sites More sharing options...
l2111 Posted November 23, 2005 Author Share Posted November 23, 2005 Thanks for everyones help. :TU: I finally solved the overheating problem. First, I got rid of the heat riser then I changed the thermostat to 160 degrees. According to the manual that is what im suppose to have. Oh and by the way it was out of gas. Thanks again everyone Link to comment Share on other sites More sharing options...
JohnD1956 Posted November 24, 2005 Share Posted November 24, 2005 Congratulations, Nicely done. I have yet to get under my 56 and check that heat riser. But I'm already running a 160 stat.Can't wait to check it out.JD Link to comment Share on other sites More sharing options...
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