Engine block drain cock for coolant change

[kenn]

I am flushing fluids and I'd like to be able to get the engine block drain cock flowing. I have removed the air element tub and lowered the side panel and I have about all the room I'm going to get without doing some serious removal. I was able to easily open the drain cock on the engine block, but as many others have found, it is blocked with "crud". I opened it and tried a small wire, plastic tube, and various other small items but I can't get any water to flow. I'd like to remove it entirely and access the hole in the block to get it cleaned out but... I'm not sure if I want to do this. I have attached a picture. I have removed the oil sender so I have room to work and I have discovered the cock has a square body. Where it is positioned gives me about 1/2 before the wrench will hit the firewall and after that there won't be any easy way to get a wrench on it. Any suggestions here? It's too tight to get my compressor hose with my air nozzle on the end of it so I'm going to have to try to find something 90* to blow air in there. I'll try that at harbor freight today but beyond that, I'm about to just button it up and flush it out.

 

[silverstate55]

It’s been many years, but I believe that I removed the fender and exhaust as well as air filter and some other parts to be able to access it for removal & cleaning….I think I broke it loose from brass elbow with an open-end wrench of some sort (I have several different lengths for each size, a whole drawer full) and possibly used a crows-foot wrench & ratchet with extensions.

BTW, it doesn’t have a square body, it’s screwed into a brass 45-degree elbow.

I hate contorting around stuff, especially as I get older….for me it’s easier just to remove parts in the way to avoid injury and/or damaged to parts or tools in the process. Plus I usually find other items needing attention/repair/replacement during this process that I would have otherwise missed.

 

[silverstate55]

Other options include (and are more likely what I used, especially a combination of these):

Offset Boxed End Wrench

Angle Wrench (link goes to Jumbo sizes, don’t know why they don’t carry the smaller sizes anymore)

Flare Nut Wrench

S-Shaped Boxed End Wrench

I use these different shaped wrenches so much I can’t remember exactly which type(s) I used but hopefully you get the idea. They usually pay for themselves the first time you use them successfully.

 

[ldmack3]

Try fitting rubber hose over the end of your blow gun held on with a clamp or tyrap. Then you can do the 90 deg.

Just curious how far the small wire went into the drain.

 

[kenn]

Other options include (and are more likely what I used, especially a combination of these):

Offset Boxed End Wrench

Angle Wrench (link goes to Jumbo sizes, don’t know why they don’t carry the smaller sizes anymore)

Flare Nut Wrench

S-Shaped Boxed End Wrench

I use these different shaped wrenches so much I can’t remember exactly which type(s) I used but hopefully you get the idea. They usually pay for themselves the first time you use them successfully.

Thanks! I hadn't considered angles but that would probably get me enough movement to work with. It looks like no-one around has any in stock so I'll probably have to order online.

 

[kenn]

Try fitting rubber hose over the end of your blow gun held on with a clamp or tyrap. Then you can do the 90 deg.

Just curious how far the small wire went into the drain.

I'm headed over to harbor freight to try to fit something - be it rubber hose, some kind of rubber cone, etc. The wire is hitting a metal "wall". It's not going in far at all. Basically to the back of the cock I guess. It's not coming back full of crud so I'm not reaching the blockage.

 

[ldmack3]

Good luck. Interested in the solution.

 

[ToddJK]

I haven't done this yet on the deuce I have now, but my older one, the coolant was pretty much a rusty coolant! I couldn't get that drain cock to open either, so I just disconnected a radiator hose and fed a garden hose in the radiator. Let the engine and water pump do the work. With water in the engine block, I added one gallon of straight antifreeze and then the rest was 50/50. I figured the block will hold at least a gallon if not more worth of water.
Wasn't a perfect solution, but it was a solution that kept a motor at regular temp and off the side of the road overheating.

 

[kenn]

A side thought... If it is just sediment/sludge that has settled and is blocking the drain, air pressure should do... something... If it is scale, I wonder if I could get away with using a long piece of tubing, hold it up, and put CLR into the tube hoping it would work on the blockage from the outside?

 

[smoke]

Just take the drain out of the 45 degree fitting. The way the drain works, it solid at the end of it. As you screw it in holes on the side of the shaft move up to allow ant-freeze to drain. So just sticking something in it won't work the way you think it should. If you don't want to take drain off the 45 fitting. Than screw it in all the way and it hit with air pressure it may push the crud out of the way. Good luck.

 

[kenn]

Just take the drain out of the 45 degree fitting. The way the drain works, it solid at the end of it. As you screw it in holes on the side of the shaft move up to allow ant-freeze to drain. So just sticking something in it won't work the way you think it should. If you don't want to take drain off the 45 fitting. Than screw it in all the way and it hit with air pressure it may push the crud out of the way. Good luck.

This is another 17/32" fitting. They must have been running a closeout on those fittings when they built my truck as my air tanks and drain cocks all have that size fitting nut. And a 17/32" flare nut wrench appears to be a holy grail item. The "T" on the drain cock prevents a flare wrench from going over the top and even in the farthest open position the flare nut wrench is about twice the thickness that is needs to be to fit over the shaft between the back of the T and the nut so it could then be slid over the nut. The brass is very soft and a crescent or 9/16 box will strip it without question.

I assume in the above you mean unscrew, as in counter-clockwise to open the valve to blow air into it. It was tight (clockwise) when I opened it up. I'm not sure I understand "screw it in all the way" as it was in all the way until I unscrewed it. *** Edit *** I am assuming that someone previously tried to drain here and left the drain cock all the way "in" thinking they were shutting it off and just left it that way. The drain cock on the radiator is backwards, I believe. You open it up counter-clockwise whereas this one seems to be the opposite.

I have opened it (counter-clockwise) until it resists going any further. I attached 3/8 ID rubber pressure hose on it and put a stainless clamp over it. At the other end of the hose, I put a blow gun with a rubber cone tip on it. I put enough pressure in it until I couldn't hold the cone in any longer and it's not letting any air through.

I don't don't have an angle wrench to get after it with so I'm going to order one of those as posted above. For the time being, I put some CLR in the line and have the hose up so the clr is, theoretically, inside the fitting. I need to get another clamp so I can put pressure in the tube and leave it with the CLR...

It seems my wrenching is over for today until I can get a wrench from that big store in the cloud. I've ordered a 17/32 tappet from flea bay and 11/16 angle from the big A. My hope is to get the drain out of the angle fitting since to remvoe the angle fitting, I have to FIRST remove the angle fitting for the oil sender. Then I have a hole that water can ingress so I'll have to make sure to seal that well FIRST...

 

[williamh]

I haven't done this yet on the deuce I have now, but my older one, the coolant was pretty much a rusty coolant! I couldn't get that drain cock to open either, so I just disconnected a radiator hose and fed a garden hose in the radiator. Let the engine and water pump do the work. With water in the engine block, I added one gallon of straight antifreeze and then the rest was 50/50. I figured the block will hold at least a gallon if not more worth of water.
Wasn't a perfect solution, but it was a solution that kept a motor at regular temp and off the side of the road overheating.

When I went to drain mine I couldn’t get mine open either. But I pulled the “plug” on the water pump and attached a garden hose to it. The radiator drain worked most of the time ( I could get to it to clean) but I just opened the hose full blast and started the truck and ran it at @ 2k until the water was clear. Took about 20 min to get clear water than let it drain and re filled with new antifreeze , 2 gallons of 100% to start and than went water , antifreeze until full as it was running. I think it holds 6 gallons total.

 

[cattlerepairman]

Different ways to get to the top of the mountain .

I usually pop the lower radiator hose off to drain. Then refill with water and add one "Cascade" tablet.
Run until thermostat opens, then some more. Let cool a bit. Pop lower radiator hose and drain.

Pop radiator hose back on, remove upper radiator hose, put garden hose into radiator and let engine run until water emerges clear from engine block.

Drain, put hoses on tight, refill with coolant, run and burp, refill some more, repeat until coolant is at the level where she likes it.

My way of doing it. I do not bother with the drain cocks at all.

Sent from my SM-G991W using Tapatalk

 

[kenn]

I have a bit of OCD and would like the parts to work like they are supposed to. That said, I'm not going to continue down this road beyond pulling the 90' fitting out and see if it drains after poking in the hole a bit with a wire. If not, I'll reassemble with a new drain cock and flush elsewhere.

On what I consider a very interesting side note, I went down the coolant flush rabbit hole as described in the TMs. They used to offer a kit called, " CLEANING COMPOUND, ENGINE COOLING SYSTEM: (oxalic acid/borax inhibitor) (81349) MIL-C-10597". It was two products - first the oxalic acid which eats rust aggressively and then followed with borax as a corrosion prevention product. It seems that long ago, prestone had an agressive flushing product that used oxalic acid but these products are no longer sold. I'm sure that the products in the military version were remarkably toxic, lol. That led me to a product from fleetguard/cummins called restore plus which is an acidic product to accomplish similar things. I have ordered a gallon but I'm debating whether I want to use it or not. Obviously if rust or corrosion is "blocking" a leak then said product may "cause" a leak. I'd also like to know that the cooling system is doing the best it can after 50 years... I'm still on the fence but the gallon is on the way here. Fittings working or not, I'll have this attacked this weekend.

 

[williamh]

The only issue I had with using any acid based product is that if it’s not completely removed or neutralized and is present in some sediment it will continue to eat away at metals and you’ll get leaks. Just like rust , it never sleeps. 🥸

 

[kenn]

The only issue I had with using any acid based product is that if it’s not completely removed or neutralized and is present in some sediment it will continue to eat away at metals and you’ll get leaks. Just like rust , it never sleeps. 🥸

If I use it, I'll thoroughly run baking soda through the system and flush with clean water following to be sure it is neutralized... I'm still on the fence. I have a couple more days to decide... The recommended ratio is about 4:1 to I'd need 2 gallons of cleaner for a 32 quart system. I'm only going to run 1 gallon so it won't be as effect (or as caustic). Anyone else yea or nay on the fleetguard flush followed by baking soda? This is the product:

https://www.cumminsfiltration.com/south-pacific/sites/cumminsfiltration-empty.bitnamiapp.com.south-pacific/files/Fleetguard_Restore_final%202021.pdf

 

[ToddJK]

If I use it, I'll thoroughly run baking soda through the system and flush with clean water following to be sure it is neutralized... I'm still on the fence. I have a couple more days to decide... The recommended ratio is about 4:1 to I'd need 2 gallons of cleaner for a 32 quart system. I'm only going to run 1 gallon so it won't be as effect (or as caustic). Anyone else yea or nay on the fleetguard flush followed by baking soda? This is the product:

https://www.cumminsfiltration.com/south-pacific/sites/cumminsfiltration-empty.bitnamiapp.com.south-pacific/files/Fleetguard_Restore_final%202021.pdf

I'd go for it. I wouldn't even worry about the baking soda. I would just flush it for a good bit. Refill with just water, run it for 15-20 mins at 1500 rpm, let it cool, drain it, flush it one more time, install new thermostat with gasket, refill with coolant. Baking soda will foam up and may leave deposits in the radiator, but it is your choice, either way, a good flush should remove the baking soda. That why if I use a cleaner, I go lite on it and just give it a good flush. That's what we used to do on cars and trucks in autotech class. Teacher always said to go lite with cleaners as some will damage or have the potential too if not used correctly. Just make sure after you run it with any cleaners or whatever, you let it cool down enough before adding cold water from a garden hose if that's route you take, just so nothing is damaged by a sudden temp change.
When we did motor flushes on some old 80's model cars that I swear never had an oil change, the grime was the lubricant because in some cases we got less than a quart of oil from the oil pan, we didn't use seafoam or motor flush chemicals, we just added a quart or two of transmission fluid since it has a lot of detergents in it, ran that for half hour and watch the crap ooze out.

 

[smoke]

I assume in the above you mean unscrew, as in counter-clockwise to open the valve to blow air into it. It was tight (clockwise) when I opened it up. I'm not sure I understand "screw it in all the way" as it was in all the way until I unscrewed it. *** Edit *** I am assuming that someone previously tried to drain here and left the drain cock all the way "in" thinking they were shutting it off and just left it that way. The drain cock on the radiator is backwards, I believe. You open it up counter-clockwise whereas this one seems to be the opposite.

Wish I was at work so I could take a pic of the drain cocks we put in our rebuild engines. Ours is turn clockwise in to drain, counterclock wise to stop draining. If you weren't reusing I say break the finger tabs of and put a socket over the end of the drain cock to get off. Than just replace with new one or a plain old hex head or square head plug.

 

[cattlerepairman]

As for cleaning chemicals, that is why I follow the advice of much more experienced folks here that have suggested the CASCADE tabs and I have been using them with very good success. They do not foam much, seem to clean the crud out quite well and do not leave residue after flushing. I am sure that dedicated acids will eat more debris but come with their own set of drawbacks.

 

[ToddJK]

As for cleaning chemicals, that is why I follow the advice of much more experienced folks here that have suggested the CASCADE tabs and I have been using them with very good success. They do not foam much, seem to clean the crud out quite well and do not leave residue after flushing. I am sure that dedicated acids will eat more debris but come with their own set of drawbacks.

Back in the day we didn't have the dishwasher pods. Never tried it, but I think I will the next time I do one. They sure clean up my dishes well,oil, grease, kids boogers, always shiny clean!