billyblankss Posted January 1 Share Posted January 1 Man I was pumped last night I got to change my oil and grease everything... Hard to find time with little kids. I celebrated by taking a drive and got exactly one mile before the cabin started smoking... I find a coolant leak and the source... It looks like maybe it's a check valve and connector for the coolant overflow, it has a directional arrow pointing towards the coolant overflow tank.... I think it's a plastic connector but it was late and dark. My questions, 1. Is this a standard part I could pick up at a big box? Or is this a special part I would need to order and from where? 2. What could I call this part, or how would I search for it? 3. Does this present an opportunity to improve the cooling system? I have seen people talk about switching from open to closed system but I've never dived into that, and I'm not sure what benefits that provides... Any wisdom is appreciated! P.s. what is this gray metal part that is attached to a clip next to this part of the cooling hose? Link to comment Share on other sites More sharing options...
TurboedMJ Posted January 1 Share Posted January 1 11 minutes ago, billyblankss said: 3. Does this present an opportunity to improve the cooling system? I have seen people talk about switching from open to closed system but I've never dived into that, and I'm not sure what benefits that provides... Imho the closed system is fine, as long as everything is functioning properly. I've had my comanche for a year and it has never overheated, except that one time the shop I used flushed the coolant and didn't burp the system🤬 Link to comment Share on other sites More sharing options...
billyblankss Posted January 1 Author Share Posted January 1 Yeah that was my instinct too and I've got the burp kit since I had to do it for my Infiniti. Still can't really figure out what to call the part that broke and how to find it though. Link to comment Share on other sites More sharing options...
billyblankss Posted January 1 Author Share Posted January 1 Ok update, it looks like this is a whole metal part with crimped ends that has rusted out at that connection site... The house branches off from I think the water pump To I think this is something like the heater core? So now the question may be do I need to be a replacement for this whole assembly? And then I guess all the hoses that are crimped as well? Does anyone have any experience with this? Is there a secret to removing these crimped hoses or do I need to buy a whole new replacement octopus? Link to comment Share on other sites More sharing options...
Ωhm Posted January 1 Share Posted January 1 Some suggestions here. CarPart com Link to comment Share on other sites More sharing options...
billyblankss Posted January 1 Author Share Posted January 1 25 minutes ago, Ωhm said: Some suggestions here. CarPart com My hero. I'm thinking replacement seems less complicated than bypassing the heater valve. Link to comment Share on other sites More sharing options...
cruiser54 Posted January 2 Share Posted January 2 It's the heater control valve. You don't even need it. There are options. I get a radiator for let's say a 1992 Cherokee. Get the heater hoses for a 97 and later Cherokee. Ditch the pressure bottle and install a universal coolant overflow tank. I'm working on a Tip to show how simple this is to do. It eliminates decades old heater hoses which are NLA, eliminates a real failure prone and unnecessary part, and gets you a new radiator without using the crappy pressure bottles. Link to comment Share on other sites More sharing options...
cruiser54 Posted January 2 Share Posted January 2 # 34 Eliminating the heater control valve in XJs/MJs Why would you want to? This valve is unnecessary and a source of leaks and complications. Jeep eliminated it as time passed and so can you. With the valve gone, radiator water flows to the heater core all the time, but your hot/cold door position blocks it when heat is off or when on AC. Your call if you must remain original for your year. In which case you probably haven’t eliminated the front axle disconnect either. Jeep also did away with that! Here is what the control valve looks like; four hoses to and from the radiator, and to and from the heater core, AND a vacuum line which controls the valve. Pull off the vacuum line and plug it securely before you forget. Your engine will tell you if you forgot! Now pull the hoses off the valve. These can be discarded, EXCEPT you likely will need some of the hose going down to water pump so, leave it in place until you decide if and how much you need and where to cut it. A big caution: be careful when you remove the hoses from the core inlets going through the firewall. The hoses will be frozen on, and excessive force could damage the heater core causing you big problems! Suggest you cut the hoses close to the core inlets, then peel back a little hose at a time and gently cut with a utility knife until you can easily twist it off. Note: the core connectors are different sizes as shown! Bottom about 5/8” and top close to ¾”. I purchased two Gates hoses as shown for a ’97 XJ, Gates numbers 19039 for the longer and 19038 for the smaller. Inspection suggests these are right—good fit! The bigger and longer hose connects from the thermostat housing, top, front of the engine and the larger connector at the firewall. The smaller hose goes on the smaller core connector and comes back to join the hose going down to the water pump. Note: this smaller hose only reaches back to the AC compressor because Jeep brought up a metal pipe in later models alongside the AC. You probably won’t have that but, you did leave the hose going down there in place, right? You just need to connect the 19038 up with that hose using a barbed, 5/8” connector, brass or PVC. You may need to cut the 19038 to fit based on the positioning of your barb connector. All you need now is to install and tighten clamps. Couple issues: Some claim the PVC connectors fail in time. I have never experienced that, but I needed a new one and bought brass (easy to find—standard garden hose 5/8” connector). Secondly, there is an argument about air bubbles and water flow with some suggesting that the larger hose 19039 coming from the thermostat should go to the smaller heater core connector on the firewall. Well, the smaller hose coming up from the water pump is pressurized, so going to the lower and smaller heater core connection seems right to me. Also, if you feel the need to switch them, then you have to cut both hoses and downsize one and upsize the other on the heater core end! For me, I just install where they logically fit by size, big end to big fitting, and they look the cleanest with nice parallel hoses. DONE! Link to comment Share on other sites More sharing options...
AZJeff Posted January 2 Share Posted January 2 I 100% endorse Cruiser's thought on ditching the fragile heater control valve. Those junky things do NOT age well, especially here in AZ, where temperatures really make plastic very brittle. There are those Jeepers who will prattle on about how removing that valve will allow the coolant to circulate through the heater core all the time and thus decrease air conditioning performance. While that might be theoretically possible, I cannot say that I have seen ANY NOTICEABLE difference. (And I say this as a guy who uses his AC most of the time, since I live in Phoenix. Link to comment Share on other sites More sharing options...
cruiser54 Posted January 3 Share Posted January 3 couldn't agree more. ^^^^^^^^^^^^^^^^^^^^^^^^^^ Link to comment Share on other sites More sharing options...
billyblankss Posted January 3 Author Share Posted January 3 13 hours ago, cruiser54 said: # 34 Eliminating the heater control valve in XJs/MJs Why would you want to? This valve is unnecessary and a source of leaks and complications. Jeep eliminated it as time passed and so can you. With the valve gone, radiator water flows to the heater core all the time, but your hot/cold door position blocks it when heat is off or when on AC. Your call if you must remain original for your year. In which case you probably haven’t eliminated the front axle disconnect either. Jeep also did away with that! Here is what the control valve looks like; four hoses to and from the radiator, and to and from the heater core, AND a vacuum line which controls the valve. Pull off the vacuum line and plug it securely before you forget. Your engine will tell you if you forgot! Now pull the hoses off the valve. These can be discarded, EXCEPT you likely will need some of the hose going down to water pump so, leave it in place until you decide if and how much you need and where to cut it. A big caution: be careful when you remove the hoses from the core inlets going through the firewall. The hoses will be frozen on, and excessive force could damage the heater core causing you big problems! Suggest you cut the hoses close to the core inlets, then peel back a little hose at a time and gently cut with a utility knife until you can easily twist it off. Note: the core connectors are different sizes as shown! Bottom about 5/8” and top close to ¾”. I purchased two Gates hoses as shown for a ’97 XJ, Gates numbers 19039 for the longer and 19038 for the smaller. Inspection suggests these are right—good fit! The bigger and longer hose connects from the thermostat housing, top, front of the engine and the larger connector at the firewall. The smaller hose goes on the smaller core connector and comes back to join the hose going down to the water pump. Note: this smaller hose only reaches back to the AC compressor because Jeep brought up a metal pipe in later models alongside the AC. You probably won’t have that but, you did leave the hose going down there in place, right? You just need to connect the 19038 up with that hose using a barbed, 5/8” connector, brass or PVC. You may need to cut the 19038 to fit based on the positioning of your barb connector. All you need now is to install and tighten clamps. Couple issues: Some claim the PVC connectors fail in time. I have never experienced that, but I needed a new one and bought brass (easy to find—standard garden hose 5/8” connector). Secondly, there is an argument about air bubbles and water flow with some suggesting that the larger hose 19039 coming from the thermostat should go to the smaller heater core connector on the firewall. Well, the smaller hose coming up from the water pump is pressurized, so going to the lower and smaller heater core connection seems right to me. Also, if you feel the need to switch them, then you have to cut both hoses and downsize one and upsize the other on the heater core end! For me, I just install where they logically fit by size, big end to big fitting, and they look the cleanest with nice parallel hoses. DONE! Hey cruiser this is a great write up and I'd love to reference the pictures you mention. I went to your site but the link to this one tip is not functioning. Can I still view that page somehow? Link to comment Share on other sites More sharing options...
cruiser54 Posted January 3 Share Posted January 3 It's in the development stage. It's actually written by a friend of mine. Link to comment Share on other sites More sharing options...
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