Academic at this point, water pump already replaced, but I’ve never gotten to the bottom of this question and remain curious. The repair manual(s) all say the coolant return pipe must be removed as part of a water pump replacement. I replaced the Corolla’s water pump without removing that pipe, and I don’t see any need to remove it.
What that pipe does? The water pump is located at the front of the engine (right side of engine compartment) , and pumps the coolant through the engine, toward the engine’s rear. When the coolant reaches the rear it goes through the radiator then is routed back to the front of the engine through the external coolant return pipe.
@LoudThunder … did you ever replace E’s water pump?
I changed it once, a long, long time ago and I do not remember anything about that back hose… But I do remember what a hassle the back hose was when I replaced all the hoses…
I have had the pump replaced by the dealer one time when we did the timing belt…
Here is a copy of my Chilton’s Repair and tune up guide for 1970 thru 1987 models… It covers the Corolla, Carina, Tercel, and Starlet. The book is numbered 7036 and it’s copyright is 1988…
If you cannot read it on your computer screen, you can click on it, copy it, and paste it into a word processor or Notepad…
Thanks for the info @LoudThunder , I can read it fine, but the water pump R & R instructions are quite different than for my 4AFE engine. I’d have guessed E has Toyota’s 4A engine, (electronic carb, transverse 4 w/timing belt). A big part of the job for the 4AFE is removing the timing belt covers and removing the water pump pulley requires removing the front engine mount & jacking the engine up. Interesting that I don’t see any reference to the coolant return pipe in your instructions.
Our engine is the 4A-LC as you can see on the engine label. Like I wrote, the back hose was only an afterthought when I was changing all the hoses and it was a bear to replace, short, stubby, and had to fit between two immovable inlets…
It’s rubber, correct (at least part of it)? Are they saying to replace it? That would make sense, by the time a water pump is needed that hose probably needs replacing. More of a preventative maintenance thing.
In the Two photos, “A” and “B” there are radiator hoses indicated between the arrows…
Photo “B” shows a top down image and under the Fuel pump there is a hose indicated, that is not the “Terror” that I wrote about previously and is relatively easy to replace… This hose is small size, like the type that goes to the heater core…
But in photo “A” there is a hose, deep down, out of sight, indicated by the two arrows. It is really short and extremely difficult to install as there are only a couple of inches to flex the hose and then get it onto the housings. As you might note in that photo, right next to the clamp on the Left side, there is the Temperature sensor for the coolant. This hose is all Rubber the same diameter as the radiator return hose (the large diameter…)
That hose is the bane of existence of anyone with big hands… I do not have big hands and I used lots and lots of Dawn dish soap to try and lubricate the hose and housings and it still drew a lot of blood and took an awful long time to work it into place. And then it leaked and I ultimately replaced both hose clamps a couple of times to stop the leak.
Good Luck, this is not something I wish upon anyone but my worst enemy…
It’s a metal pipe on the 4AFE engine. About 2 inches diameter. Appears to be galvanized steel. And has a couple of stubs out the side for rubber hoses going to other places, like the passenger compartment heater.
@LoudThunder 's photos don’t show that pipe, so maybe his 4ALC engine doesn’t have it. But the photos don’t show the exact area it is located either. In photo “A”, the right arrow is pointing to the rubber hose. On mine that hose connects to the metal coolant return pipe. Photo “A” shows a small part of the intake manifold (the bright shiny metal), and the coolant return pipe is bolted directly to the engine & located directly under the intake manifold. Very difficult to access for a diy’er working on the ground. With a lift it probably would be fairly easy to access for a pro.
It’s easier to see the other end of that pipe near the front of the engine, b/c that’s where the water pump is located. The water pump connects directly to that pipe. The coolant returning from the radiator goes into the water pump’s intake port, then through the water pump and pumped into the engine. So the water pump has two water-tight o-ring connections, at the coolant return pipe and the cylinder head.
The instructions aren’t clear why the pipe is supposed to be removed. Maybe it is to inspect for the amount of internal corrosion. But my guess it is to insure the new water pump makes a watertight connection to that pipe. If that pipe were warped the flanges might not meet up square to each other. If you connect the water pump to the pipe while it isn’t attached to the engine, then less likely for that to occur. When I connected the water pump to the engine I made sure the two flanges (water pump’s and coolant return pipe’s) were in line & parallel to each other, so I made the executive decision to not mess w/that pipe. Removing it and re-installing would have been a bear working under the car from the floor. Just to make it interesting, There’s about a bizillion things that will scratch your arms nearby to that pipe … lol …
I have been searching for two days to find information on the rear coolant hose you are indicating, I bought the cable type spring clip remover but the the tabs on the clip are just in the right place to be wrong. How did you get the spring clip off behind the motor? please please please tell
If I remember correctly, the removal was somewhat “destructive,” I seem to remember cutting all the old hose out and I only had to deal with hose ends still on the housings… One clip was accessible, however I use a moto-tool to cut the other one off.
Believe it or not, that part was easy, then you have to get the new hose back on, use lots of soapy water and a set of mechanics gloves as you will mash, gash, and/or slash your knuckles trying to get that hose back on.
It is not like there is any “free play” on the hose where you can flex it until you can slip the other end on. If this does not make sense, it will once you try to install that hose back, I would not recommend you using the squeeze or spring clamps to reinstall it, they will only make it that much more difficult to install the hose with them already installed on the hose. Use the Screw style hose clamp…
Thank you much I was able to get a hook under the bottom lip of the spring clip to pry it up through a hole in the intake manifold just enough to get the cable style spring clip pliers just barely on it, but then trying to move it I got it almost off and then the clip slipped out in an even worse position. Just curious what is the shop procedure for replacing that hose?
I do not know what the “Shop Procedure” is or rather, was; as I imagine most mechanics whoever worked on my 40-year old Toyota are long retired.
What I described was my “home garage procedure” as my wife sat by telling me to stop “hurting” Eleonore (the name of her car… She is the original owner)…
No room for any of that, thought I was slick with a doubled up piece of cable to make a noose in a pipe through the intake manifold but it just slipped under the tab between the hose. Pointy vise grips, needle nose, couldn’t get my hand around them to use any pressure.
Setting up a lap top and usb camera so I can see under there, It’s like surgery through spaghetti. Are there any vacuum hoses under there to worry about?
You are having problems getting the clamps off, is that correct?
Take your smartphone, set it on video with the flash turned on and slowly, very slowly, move it around, fasten the phone to a ruler and you will have extra reach. Do this from the top and the bottom, you should be able to see anything in your way, and I do not think you will find anything else fragile or soft down there…
When I say slowly, I mean really slowly, like you are tracking a snail… filming that close and even a slight movement looks like you are swinging the phone around… You’ll see…
Even if you can get the clamps slipped off the ends of the hose, or into the middle of the hose so they are not clamping done on the housing, the hose is hard, the hose is probably stuck to the housing and then you still have to slide it off somehow and you know there is almost no room to do that.
I say, destroy the hose, cut it, slash it, use a “light sabre” or whatever else is in your arsenal and then you only have to deal with the ends of the hose and the stubborn clamp and get the screw style clamps to put it back on…
Have you tried from under the vehicle?? Through the fender well maybe?? It has been years but I have done a few head gaskets on those old Corollas and don’t remember it being very hard…
