james l meyer Posted March 22, 2018 Share Posted March 22, 2018 My 1935 buick 56s keeps overheating because when it gets warm it dumps the antifreeze out of the radiator overflow. recently rebuilt engine. my mechanic put a new internal spring into the radiator but that did not help. he put in a spring he had on hand so I'm wondering if he put in the wrong spring. any suggestions? Link to comment Share on other sites More sharing options...
Matt Harwood Posted March 23, 2018 Share Posted March 23, 2018 Is it actually overheating or just puking coolant? It's common to over-fill the radiators on old cars to the very top, but they don't like that and puke. Just filling it to the top of the core and leaving room at the top of the radiator for expansion usually eliminates the problem. Or just let it puke and it'll find its own level. On the other hand, if it's actually overheating (either blowing steam or showing too hot on the gauge) there are things to check. If it's just showing hot on the gauge, double-check with a second gauge to be sure it's accurate. If it's blowing steam, then you definitely have a problem and should start doing some diagnostics. I'm not sure what you mean by a spring in the radiator (maybe the spring that controls the radiator shutters--are they opening?). Can you confirm whether it's actually overheating? Once you do that, we might be able to give you some better advice and next steps. Link to comment Share on other sites More sharing options...
trimacar Posted March 23, 2018 Share Posted March 23, 2018 Check the packing and/or water pump grease. If either fails, the water pump will suck in air, cause foaming, which dumps out the overflow. A water pump is a very neglected part of antique car maintenance... 1 Link to comment Share on other sites More sharing options...
Grimy Posted March 23, 2018 Share Posted March 23, 2018 I'll bet the spring he added was inside the lower radiator hose to keep it from collapsing inward under suction. I'm trying to remember the lower hose routing on my long-gone 1934 56S (great cars, by the way, so congratulations!). Most cars of this period had metal tubing (replace with stainless exhaust pipe tubing) so that each connecting hose from pump inlet to lower radiator neck/outlet was no more than 4 or 5 inches long between metal pieces--to prevent such collapse. The original way is preferred. Get a shop manual: 1934 and 1935 Buicks are virtually identical. Have you removed the water jacket plate on the driver's side, behind the intake and exhaust manifolds? If not, you may find a huge buildup of rust and debris especially between the rearmost cylinders--that must be cleaned out, and it's a tedious job but necessary. Pay attention to how eroded that water jacket plate is on the inside. Braze any pinholes, perhaps apply an epoxy coating, and be sure to use plenty of anti-corrosion additive. I'm a true believer in using a nylon stocking as a coolant filter. Search the forums for stocking filters. If you can't find it, tell us so and I'll re-type. And please post photos of your car. Link to comment Share on other sites More sharing options...
MCHinson Posted March 23, 2018 Share Posted March 23, 2018 I am only guessing that the 35 bypass valve is similar to the 1937 and 1938 Buicks that I am familiar with. If the bypass valve is not operating properly, coolant bypasses the radiator and causes overheating of the engine. Do you have a factory service manual? If you are interested I can send you a Torque Tube II issue that discusses causes and cures of overheating in 36-38 Buick engines. Link to comment Share on other sites More sharing options...
Grimy Posted March 23, 2018 Share Posted March 23, 2018 Matt, I know the 60 and 90 series had the bypass, and the 50 MAY have had it--too long ago, But you are absolutely right. And if the 50 doesn't have the bypass, he should still drill two 1/8 inch holes in the base of the thermostat. Link to comment Share on other sites More sharing options...
james l meyer Posted March 23, 2018 Author Share Posted March 23, 2018 First of all thank you all for responding. This is a great forum. No question it is overheating. I drove the car 6 miles home and it dumped a gallon of antifreeze, I measured it and got hotter than I like but NOT so hot that it was blowing steam. If I had not stopped and added water back into the radiator it would have continued dumping water and gotten too hot. I'm running without a thermostat. It is warm enough here that I don't need it. I do have the manual. My mechanic had it when he changed the spring. From reading the manual it appears to be the spring that operates the "thermostat valve". (I scanned the pages from the manual ). The book states that this valve is shut when the car is first started, until it reaches 140 to 150 degrees then as it opens it allows the fluid to recirculate through the cylinder block and head. It definitely is not the spring in the hose. I repacked the water pump. I have been frustrated with that because it still leaks. I may have screwed that up because I did not put any grease in with the packing so it may be sucking air and that may be why I could never get it to stop dripping. What type of grease should I use? Unless it is sucking air and causing a problem it is not the water pump that is dumping the antifreeze. I definitely know that the dumping of the antifreeze occurs from the overflow that starts at the cap and runs along side the radiator. And it starts shortly after the temperature reaches 140 on my gauge. I looked but I could not find the "water jacket plate" so I don't know if I have one but since the engine was just rebuilt that would have been cleaned, correct? Is it on the block and surrounded with bolts? ( I only have about 200 miles on the rebuild. It has been overheating and I can't break it in. My rebuild guy was slow but very good) After reading the manual and writing this I am more convinced that my mechanic was right the "thermostat valve" spring needed replacing but I believe he put the wrong spring in and it is still not working. AND/OR I need grease in with my water pump packing material. Again, Any comments or suggestions would be appreciated 07261406.PDF Link to comment Share on other sites More sharing options...
60FlatTop Posted March 23, 2018 Share Posted March 23, 2018 (edited) 14 hours ago, trimacar said: Check the packing and/or water pump grease. If either fails, the water pump will suck in air, cause foaming, which dumps out the overflow. A water pump is a very neglected part of antique car maintenance... My first thought. Neglected, only second, to the rear axle lubricant. Bernie Edited March 23, 2018 by 60FlatTop (see edit history) Link to comment Share on other sites More sharing options...
Matt Harwood Posted March 23, 2018 Share Posted March 23, 2018 First, put the thermostat back in. The thermostat doesn't control the maximum temperature, it only controls the minimum temperature. However, it also slows the flow of the coolant down enough that it stays in the radiator long enough to cool off. It's the restrictor plate in the system and if the factory engineers thought it was necessary, don't second-guess them. They were pretty smart. If it's not steaming, it's not overheating. You're losing coolant. Not quite the same thing, although one will necessarily lead to the other. You need to figure out why it's pushing the coolant out the overflow and it doesn't sound like it is because it's boiling off. 140 degrees isn't hot at all. I had a client with a '38 Packard that would do exactly what you're describing--it didn't blow steam but it constantly lost coolant--so much that you could see it coming out as he drove and the cars behind him were always covered in coolant. He tried all kinds of remedies but it ultimately turned out that the water pump was pushing the coolant through the radiator too fast. The flow rate of the radiator couldn't keep up and the excess coolant was backing up on top and flooding out the overflow. Packards didn't have thermostats, they had radiator shutters to regulate temperature, so we modified the water pump fins to be a little less aggressive. Problem solved and it ran cooler to boot. The thermostat in your cooling system may provide the same solution. I'm not terribly well-versed in the specifics of your cooling system, but I might also think that if there's a bypass with the wrong spring, it could be causing the same issue by either opening too soon or too far. Also note that a little leaking from the water pump is normal--it's liquid-cooled and the seeping keeps the bearing and seals from overheating due to friction. There's a reason why full-service gas stations existed--losing a little coolant is normal and this is one of the normal places to lose it. There's a solution and I bet it will be a minor one that will make everyone hit their heads and say, "Oh, of course!" Link to comment Share on other sites More sharing options...
auburnseeker Posted March 23, 2018 Share Posted March 23, 2018 Buy one of the cheap infrared noncontact thermometers, they will take a lot of guesswork out of things and are a very important tool when buying a car. Gauges back then are far from accurate. With the thermometer you can see your radiator temperature top to bottom to make sure the antifreeze is cooling enough before re entering the block at the bottom. I think around 20 degrees is what a healthy one usually reads. I understand this doesn't necessarily address the coolant push off, but it will help you get a good handle on the health of the system. It will also let you see if there are any hot spots in the engine. Good luck. I had a 48 Caddy that did the same thing, but eventually getting a correct thermostat in it and drilling the bypass hole in the stat cured it. Link to comment Share on other sites More sharing options...
MCHinson Posted March 23, 2018 Share Posted March 23, 2018 I would replace or rebuild the water pump. I would also find a source for a correct bypass spring, or else block the spring so that the cooling system cannot go into bypass mode. From your pdf, the bypass valve on a 1935 is physically different, but serves the same purpose as those that I am more familiar with. It is designed to bypass the radiator to get the car up to optimal operating temperature fast. A few minutes of cooler operation is much better than having your coolant recirculate through the block, bypassing the radiator, when the car is warm. If that spring is too weak, the coolant bypasses the radiator and you get overheating. A common fix in 36-38 buicks is to block the bypass valve so it cannot go into recirculating mode. Link to comment Share on other sites More sharing options...
Rusty_OToole Posted March 23, 2018 Share Posted March 23, 2018 I would start by blowing out the rad from behind with compressed air. Get rid of 80 years of dirt and bugs, and costs nothing. You are supposed to leave a couple of inches space in the rad for expansion as others have pointed out. Likewise with needing a thermostat. Not only does it slow down flow, it keeps a slight pressure on the pump to prevent cavitation. An infrared thermometer will tell you the correct temp, and you can use it to check if the back of the block is the same temp as the front. This could be important if something is interfering with coolant flow, unlikely with a new engines but worth checking. If the infrared thermostat reveals hot and cold spots in the rad it could be blocked, cold spots reveal areas with no coolant flow. In that case the rad may need to be cleaned or replaced. Link to comment Share on other sites More sharing options...
60FlatTop Posted March 23, 2018 Share Posted March 23, 2018 I didn't see anything about the thermostat being removed in the first post. That is something you need. There have been times when I cheated and knocked the element out and just left the plate in as a restrictor. If anyone has a index for Skinned Knuckles articles, I remember a really good one describing the high/low pressure sides of a car cooling system. The thermostat restriction maintained a higher pressure in the block back to the outlet of the water pump. The temperature/pressure relationship of the coolant has a higher boiling point under pressure, greater than 212F. The suction side of the pump influenced the system on the cooling side of the thermostat. That kept the coolant from flashing off to steam under the lower pressure. That was pretty much the concept. The article when into greater detail. Better pump seals, overflow tanks, and improved coolants have changed that philosophy and reverse cooling flow became common with the GM LT1 engines. The coolant flows from the radiator through the heads at its coolest temperature, to allow advanced timing for HP and economy, gets hotter in the block, and is drawn into the pump at operating temperature. More than anyone needs to know, but I am waiting to go out to dinner. Also reflecting on almost 60 years of fixing stuff. My greatest successes have come from taking out "improvements" and bringing things back to the original intent and specification. Bernie Link to comment Share on other sites More sharing options...
trimacar Posted March 23, 2018 Share Posted March 23, 2018 5 minutes ago, 60FlatTop said: My greatest successes have come from taking out "improvements" and bringing things back to the original intent and specification. No kidding. Some people think that the engineers back then were total failures, and so try to "improve" things, when in reality it's deviation from the original that causes the problem. If our antique cars were hard to start, hard to steer and brake, and overheated, when brand new, does one really think they would have sold? Most problems are related to improper maintenance, incorrect lubrication, corrosion, and inactivity of the car. 3 Link to comment Share on other sites More sharing options...
MCHinson Posted March 23, 2018 Share Posted March 23, 2018 I agree that the thermostat is part of the original system and needs to be in it, but I am also quite sure that a 1935 Buick cooling system is a non-pressurized system, since Buick still used a non-pressurized cooling system in 1937 and 1938 as well. I think that Buick went to a pressurized cooling system in 1940. Link to comment Share on other sites More sharing options...
auburnseeker Posted March 23, 2018 Share Posted March 23, 2018 That being said, the Original poster will want to make sure they have the correct radiator cap and not one that is pressurized. Lots of things get changed over time. That has to be one that is most often replaced with an incorrect one because it "fits". Link to comment Share on other sites More sharing options...
Spinneyhill Posted March 24, 2018 Share Posted March 24, 2018 What is the spring pushing on again? Some kind of thermostat-like device? Is it failing to open at all? Is the return water way completely closed? I just went through this with my Dodge 8. It pumped coolant out. It came home on a flat bed tow truck. I bought an IR thermometer and determined it was pumping fluid when the thermostat should have opened. I had the radiator cleaned (rodded) - I tried the air and water sparging but not enough came out. It pumped coolant out when the clean radiator went back in. Again, when the thermostat should have opened. I notice the outlet neck on top of the head was cool, meaning the thermostat was not opening. I tested it: sticking closed. I replaced it with a new one that worked (I tested it). It pumped coolant again. Grrrrr. The outlet neck on the head was still cool. There was a lot of gurgling as I refilled the coolant and the refill was slow. I guessed the thermostat was blocking air coming through as the engine filled with coolant, so there was an air bubble under the thermostat. Air is not a good conductor of heat so the thermostat stayed closed. I drilled a wee hole in it - about 2.5 mm, whatever the drill was in the drill press. This allowed air out of the block and head and a tiny circulation of water during warmup. That fixed it! Put the thermostat back in! You want the fastest warmup possible to minimise wear, most of which occurs when the engine and oil are cold on startup. Link to comment Share on other sites More sharing options...
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