Carburator / Manifold / Head Removal (2 Viewers)

[lcolon]

I am going through the pain yet again of pulling apart my engine due to mysterious overheating problems. Symptoms are that at idle the temp stays at 180-190o. On the highway, the vehicle overheats and the temp climbs to 220o (not good). The following has already been done: new radiator, new thermostat, new water pump, all new cooling lines, manifold removed - rebuilt - decked flat. Chemical block test is negative and compression (cold) varies from 125psi - 165 psi depending on the cylinder. The current head as approx 10-15k miles since the last one was replaced as it had cracked. Given that all of the above has not resolved the problem, I am going to pull the head off again to have it checked by the machine shop to rule out any other potential causes.

To benefit the mud community as I have never seen a walkthrough of this procedure, I am documenting the steps with a number of pics as it may help someone else...

Barring any rusty / hard to remove bolts - total time to strip the vehicle down for Phase 1 (manifold removal) takes me 3ish hours working at a good pace. Given my rig keeps coming apart and going back together fairly frequently, things tend to move along fairly quickly. This job does have its challenges. Not difficult but tedious, and at times are real pain in the neck, back, and arms.

Prerequisites:

• Aquire a six pack 24 pack of adult beverages as you are going to need it
• Get a box of quart baggies, a sharpie, and some masking tape to contain bolts and label vacuum lines

Carburator Removal
Note the steps are setup in here in case someone just wants to remove the carb without digging further into the engine
Step 1 - Remove the air cleaner assembly from the engine

Step 2 - Remove the air rail and valve cover- I always do this as it makes it easier to access the bolts on the engine side of the carburator without the rail in place. Some people use a "cut down" wrench to assist with the carb base nuts and may be able to skip this step.

Step 3 - remove the vacuum lines that connect the carb to the vacuum manifold and label them. There are 4 on the engine side of the carb, 1 on the front side, the A/C idle up on the drivers side, and the large one next to the fuel cut solenoid plug. Remove the electrical connector to the fuel cut solenoid. Disconnect the metal fuel line.

Remove the carburator linkage. There is a small cotter pin that must be removed to disconnect throttle arm and you can simply pop off the rod that leads down to the drivers pedal.

Step 4 - loosen the screw to the choke cable and remove the choke cable from the carburator

Now using your trusty short 12mm wrench, loosen the 4 nuts at the base of the carb. It helps to lift up on the carb once they are loose to remove the nut completely. Remove the carb from the vehicle.

Intake / Exhaust Manifold Removal

Step 4 - Drain the coolant. An unfortunate part of the 2F design, is that the vacuum manifold and the carburator fuel line are both bolted to the thermostat housing. You can simply remove the upper passenger side hose initially and drain the coolant from there. That hose is easily aimed down the front of the engine toward an awaiting bucket. I have found that this will limit the amount of coolant removed to about 2 gallons as opposed to having to drain the whole radiator.

Remove the vacuum manifold lines from the various accessories. Make sure you label them, have a good memory, or have the emissions manual handy during reassembly. Now is a good time to ensure that everything is routed correctly.

 

[lcolon]

Step 5 - Remove alternator, tensioning screw from A/C compressor, and fully remove alternator bracket assembly. Remove 10mm bolt on the side cover holding on to the fuel line. The bracket removal is necessary to access this bolt. I simply lay the alternator on the passenger side of the engine compartment and do not bother disconnecting any of the electrical connections.

Step 6 - remove the coolant lines attached to the top of the thermostat. Remove the 2 mounting bolts for the thermostat housing to the head. You may find it easier to remove the thermostat housing cover depending on your wrench set. Remove the thermostat housing from the head

Step 7 - Remove the 2 bolts securing the carburator insulator plate to the manifold and remove the insulator. Lay the vacuum manifold and carb fuel line off to the passenger side of the engine.

Step 8 - Now the real fun begins removing the manifold. I do not have pictures of all of the bolts, but here is the basic procedure:
a. Unbolt the EGR and pipe from the manifold. Loosen the nut holding the EGR to the pipe that goes into the manifold and separate them
b. Remove the 3 nuts that hold the exhaust pipe to the manifold. A couple are accessible from the top, the other you will need to crawl under the truck to get to
c. Remove the bolt between the EGR pipe (the corrugated one) and the manifold (located below the valve and above the cooler)
d. Remove the bolts (2 ea.) for the 2 heat shields bolted to the manifold and remove the heat shields
e. Working under the truck with a long extension, remove the 2 nuts connecting the j-pipe to the manifold
f. Loosen the 2 bolts holding the EGR cooler to the block (this makes the j-pipe disconnect / re-connect much easier
g. Remove the bolt on the clamp under the truck holding the exhaust downpipe to the engine
h. Remove the skid plate
i. Remove the 3 bolts connecting the exhaust downpipe to the catalytic converter (some may have frozen bolts or a welded in cat - if so i would try to loosen up enough exhaust mounts that there is some freeplay in the overall system to allow for a disconnect)
j. Remove the bolts and nuts holding the intake / exhaust manifold to the block. For the bolt up against the firewall, it helps to have a long ratchet that gives enough reach and movement to remove it.

Step 9 - now that all the bolts are removed, wiggle / pull back on the manifold to clear the studs. You may really need to wiggle it around to get it to disconnect from the j-pipe and exhaust. Once clear lift it up and out. Note that the assembly itself is fairly heavy so can require some brute strength to do this

Rejoice with some adult beverages that you have come this far. Tomorrow or the next I will post up the final steps for head removal once it is completed.

 

[batthewmrown]

Man, this is a killer write up and is a huge help. If you wind up in Denver, I owe you some beers.

 

[NYIronPig]

 

[OSS]

How was "overheating" verified without a doubt?

 

[lcolon]

Man, this is a killer write up and is a huge help. If you wind up in Denver, I owe you some beers.

Thank you. Denver is a wonderful place. Gotta get the cruiser back on the road to get an excuse to drive out there to do some wheeling/dirt bike riding.

How was "overheating" verified without a doubt?

I questioned everything. At one point I tried: Mechanical sender in the stock location, new toyota sender in stock location hooked up to a multimeter. I was measuring the resistance and comparing it to the chart that is available here on mud. I acquired a fitting that fit into the upper radiator hose and ran the mechanical sender there. I ran the truck with a new thermostat and without a thermostat. Finally I borrowed a calibrated reference thermometer with the appropriate fitting for the upper radiator hose from a friend of mine who uses these tools for adjusting industrial equipment. The reference thermometer confirmed the overheating situation and that the mechanical gauge works correctly. In addition to all of this, utilizing a IR heat gun on the radiator and various parts of the head and coolant lines.

Needless to say a mind bending saga. I will post the rest of the head removal writeup tonight. While the head is out I am thinking of pulling out the radiator and having it flow tested (even though it is new) to rule that out. I did find what looks like a burned valve on the #1 cylinder (ironically the one with the best compression). Will see what the machine shop says once I get the head to them.

I certainly don't wish this process and headache on anyone. The cruiser has been like an anvil for reliability for the last 100k+ miles that I have owned it. Over the last 10k, a real pain with overheating.

I think I am infected with the covidcruiser sickness

 

[OSS]

My engine developed running/too/hot issues later in life and after removing the head I discovered why- the head gasket cooling holes were wrong (I had used an aftermarket head gasket) and they had grown gummy deposits around them impeding water flow.

After replacing the HG with a Toyota gasket and changing the coolant (and getting a new radiator, thermostat and Fan clutch) the engine ran at the correct temperature.

You're really close to nailing this down. Just don't assume any of the things you replaced with new are working to spec/ test the thermostat

 

[Rusto]

Nice write up. We're in similar states of disrepair right now, as you know. I did use the stubby 12mm for the carb as I don't have to take my valve cover off. Other than that, a very familiar process.

1 tip that I plan to add to my thread when I'm done is a list of tools required for the job.

The pictures help quite a bit.

Q: what paint did you use for your exhaust manifold?

 

[60 toy ota]

Very nice detail and writeup. I followed these basic steps the first time or two I removed the head. Then I tried removing the head, carb, and manifolds all together and it worked great. Saves a lot of time if you have something overhead to hoist from

 

[lcolon]

Nice write up. We're in similar states of disrepair right now, as you know. I did use the stubby 12mm for the carb as I don't have to take my valve cover off. Other than that, a very familiar process.

1 tip that I plan to add to my thread when I'm done is a list of tools required for the job.

The pictures help quite a bit.

Q: what paint did you use for your exhaust manifold?

The exhaust manifold I had ceramic coated. The machine shop I used (Yota1 in Riverbank, CA) split the manifolds and sent the exhaust section out for the ceramic coat from their guy. Results look really good and the stuff does not burn off.

Very nice detail and writeup. I followed these basic steps the first time or two I removed the head. Then I tried removing the head, carb, and manifolds all together and it worked great. Saves a lot of time if you have something overhead to hoist from

In my next life I will have a garage, a gantry crane with a beam integrated into the ceiling, and a bunch of other stuff. I am sure that would be the easiest procedure. 16 head bolts, 1 ground wire, some coolant draining, rock and roll! Particularly if a desmog is in place.

 

[lcolon]

So for those who have been waiting - or have sadistic tendencies to see my struggles with a Cruiser, the head removal ...

Step 10 - Remove the ground wire from the head if not already done. Remove all of the spark plugs.

Step 11 - Drain the block coolant (avoids spilling a bunch of coolant into the cylinders when the head is removed). Bolt is located on the drivers side back toward the bell housing. I did see a post on Mud somewhere of a cruiser head who does this so often, he fitted a valve with a downspout to make it easy.

Step 12 - Remove the rocker arm assembly. Start by loosening the bolts / nuts, a little at a time, working outside -> inside (ie. start with your #1 side, loosen each bolt a few turns, go to #6 loosen a few turns, go to the next inner mount point on the rocker arm near #1 loosen those, etc.). It should take 3 -4 passes to get it all loosened up. The process is tedious but it avoids any tweaking to the assembly (maybe I am just anal about this stuff). Lift off the rocker arm assembly. The pushrods should be removed and labeled so they go back in their original locations. A spare box makes an easy way to mark everything.

Step 13 - Break loose all of the head bolts - Using a long 1/2" drive breaker bar, break loose all of the head bolts. This can be tough and require a cheater pipe to be slipped over the end. As much as I think about it, I resist using my air impact on the bolts for fear of breaking the heads off the bolts. My setup consists of a deep impact rated socket (they fit tight on the bolt head and will not break under pressure), and a 25 in breaker bar (from harbor freight 1/2" drive 25in breaker bar works for me!... I always keep this bar under the drivers seat of my truck as it helps with the wheel lugs in an emergency. HF now sells a longer one that I might need to buy). The swivel head on my bar combined with the deep socket fit perfectly for the bolts up against the firewall and coolant pipe. Never had a problem with access to these. Head bolts should be broken in reverse installation order. Work the outside bolts first, then work in. The last bolt should be the one in the center of the head.

Head bolts should be broken loose first, then loosened a little at a time in the same sequence. Remove all of the head bolts. Before the head can be removed, the seal to the head gasket must be broken. Using a prybar or a very large screwdriver, CAREFULLY lift up on the head at one of the prying locations. The blue arrow shows one on the passenger side. There is another good spot on the drivers side, same location. You can lever off of the power steering pump stand. Goal is to just get the head to lift slightly off the block.

 

[lcolon]

Step 14 - Lift the head off the block. The head is HEAVY = must weigh 90lbs or so. Do not attempt this alone as it could do some damage to your back. I have watched videos on youtube of people doing this solo and my bulging disc gives a twinge every time. Better method - get a friend and pay him with some of the adult beverages that I outlined as a prerequisite at the start of this thread. I should have taken a picture of the rigging but failed to do so as my buddy only had a limited amount of time and we were concentrating on getting the head off. Some people remove the hood from the truck. It provides better clearance but not necessary.

My method consists of a light chain from homedepot (you don't need anything crazy big. Small chains can still support over 300lbs of weight. I have put a picture below of the chain I use). You can utilize the ground bolt, alternator bolt and some manifold bolts to connect the chain to the block forming a loop. Have a 2x4 long enough to clear the fenders and a person on each end. The head can subsequently be lifted off to an awaiting piece of plywood on top of the fan shroud. Another idea is to attach the chain to the 2 inner rocker arm studs / valve cover suds. The valve cover bolts can hold the chain on. This will center the head nicely for the 2x4 lift off. I have heard of many other methods, the chain works for me. So with your buddy, lift that head off onto the top of the fan shround / radiator (small piece of plywood). You can then both grab it and walk it to your final location.

In my case now witness the bottom of the head... obviously #1 cylinder exhaust is getting burned. I think in my case it was from a vacuum leak at the manifold from a previous non-straight manifold I had on there. The machinist will let me know what the next steps are. Hopefully the damage is not too bad.

 

[lcolon]

I just got my head back from the machinist. Luckily no cracks but they had to grind the #1, #3 exhaust valves.

The threads on my valve cover studs are junk. Does anyone know of a good source for 4 studs? Toyota no longer makes them and I am not sure if there is an aftermarket option or only available new.

Perhaps there are other options... 3F studs?

 

[Seth S]

I just got my head back from the machinist. Luckily no cracks but they had to grind the #1, #3 exhaust valves.

The threads on my valve cover studs are junk. Does anyone know of a good source for 4 studs? Toyota no longer makes them and I am not sure if there is an aftermarket option or only available new.

Perhaps there are other options... 3F studs?

@ToyotaMatt has those studs I do believe.

 

[ToyotaMatt]

I just got my head back from the machinist. Luckily no cracks but they had to grind the #1, #3 exhaust valves.

The threads on my valve cover studs are junk. Does anyone know of a good source for 4 studs? Toyota no longer makes them and I am not sure if there is an aftermarket option or only available new.

Perhaps there are other options... 3F studs?

@ToyotaMatt has those studs I do believe.

i do not have any rocker arm shaft tower studs

i would try @65swb45 , mark can set you up

what is wrong with your current studs ?

 

[lcolon]

i do not have any rocker arm shaft tower studs

i would try @65swb45 , mark can set you up

what is wrong with your current studs ?

The last shop (not the current one) that redid my head damaged the threads at the top. Looks like they were all grabbed with vice grips and the threads crushed. I had recut them but the metal was getting very thin. The machine shop I took the head to this time agreed and tossed them out. I have them trying to see if they can source some and I thought I would post here if anyone has some others.

Thank you for the reference I will see if Mark has any... $OR does if no one else does.

 

[Seth S]

I am ignorant to the stud details but are they unique in design?

 

[lcolon]

I am ignorant to the stud details but are they unique in design?

Yes they are. They have 2 different sized threads on them. The bigger size for the nut that locks the rocker arm assembly to the head and the top part is smaller for the valve cover bolts.

 

[lcolon]

Got the head masked off and painted. Even though I have a new brass radiator, given all my overheating issues and for the avoidance of doubt, I picked up an aluminum champion radiator for a good price. I ran one of these previously with excellent results. I will put this in instead of the brass one. Once I get it out, I will have the brass one fully tested to see if it was plugged for some reason (shouldn't be because of it being new). Nothing else to rule out at this point once it is all back together.

Just waiting for my head gasket and need to source those dang studs for the rocker arms.

 

[Seth S]

The good thing is that there is a large assortment of step studs available. Just need the thread spec and length.