Bobcat 632 - Blown Head Gasket?

[bobcatzack]

Hey Zack, just for the record, that thing you're calling fuel filter is actually a fuel pump. Not that that really changes anything, I'm just trying to help you identify parts. Also, you mentioned fuel solenoid. I didn't see a solenoid in there. If it matters, post a pic of what you're calling a solenoid. Again, only if it matters to ya.

Guys he's doing this in his garage all by himself. He'd never done anything like this before, and he's just charging in, and learning along the way. I got a lot of respect for that! After all, isn't that how we all got started? You're doing great Zack.

Hi Pete, those are incredibly encouraging words!! Sometimes I start thinking to myself that I may have gotten this far by chance, and if I try to proceed any further (I.e. messing with pistons/crankshaft etc) I might begin to cause more harm than good, and might come to a point where there might not any turning back to where things were (at the least, the Bobcat used to crank and start!). On top of that, any machine shop I am calling in the area are backed up on engine repair work for about 2 months.
In any case, with these encouraging words, I will be attempting to hang the engine up on 750lb pully system I installed on the garage ceiling (pic attached below) then try to get fitted onto an engine stand that I bought on amazon. If successful on the stand, attempt to rotate it and remove the oil pan. Then see if I would be able to remove the pistons without disturbing the crankshaft assembly.
I will then try to get the engine block and the head into my van and drive to a mechanic who is willing to inspect the cylinders for damage, and as well suggest any fix (such as honing etc).
(Btw thanks for the fuel filter/fuel pump correction!)

 

[bobcatzack]

https://www.oreillyauto.com/detail/c/precision-fuel-pumps/precision-26-gph-fuel-pump/pfp0/e16010

I used a pump similar to this one, first, but it failed after less than a year. It was from AutoZone. After it failed while pushing snow, I put this one on ad or was the only one in stock. It is both longer and bigger around.

My mechanical block mounted fuel pump has totally failed and the top cap popped off, so I just left the rest of it there to fill the hole in the block. I replaced all the rubber line a little at a time - I should have just changed it all at once, but alas here we are.

I bolted the pump down vertically at the front of the intake, using a 5/16th 1 inch bolt (and I washer or two to take up extra bolt length). It is grounded through the dipstick mounting bolt, and gets power through a relay I added that is triggered by the fuel solenoid line found under the governor/distributor/carb.

Pic *217 is overall mounting of pump... It popped out of the mount, I'll fix it when I'm not kneeling in 2 feet of snow.

Pic *142 is the bracket... Apparently my pump slipped out! But you can see the adapter film 5/16 (not 1/4 inch like I thought) to 3/8 hose. I need to tidy this all up.

Pic *201 is the trigger lead for the relay. This is the trigger for the carburetor solenoid. The factory harness on my truck is a pair of yellow wires with a female 1/4 spade connector. I have a spade piggy back connector inline going to my relay, then onward to the carb solenoid (the funny sheet metal "U" bracket).

Pic *152 is the relay. And other garbage. Again, kneeling in snow. I'll clean this up in a few months. Hey, at least I have fuses!

Thank you for the details and the pics!

 

[bobcatzack]

Exactly! Keep it up Zack, you'll be the best expert on YOUR machine!

Thank you!!
Not sure if I would be expert, but perhaps an adept novice who hopefully won't have to look back and say "don't EVER tinker with something you have no idea about!!"

 

[bobcatzack]

I will hopefully clear up a bit about my own fuel system. Once my fuel line enters the engine compartment, from the fuel shut off and filter, it changes from steel line to rubber tubing. I replaced all the rubber tubing. My machine does not have any electronic solenoids in-line or in the carb as some do. When I went through my engine I wanted a new fuel pump only because it is difficult to reach and I did not know the age of it. I bought a new mechanical fuel pump from an auto parts, all seemed fine until I found that the choke would not work. The linkage hit the outlet tube of the new pump. I could not find a duplicate of my original pump. After a couple of weeks I considered using a choke cable instead of hard linkage. I hook that all up and did not like it. I could imagine water getting in the cable and freezing in the winter....back to square one. After an even longer search, I indeed found the exact fuel pump and all worked out perfectly. On the photos attached you will see the difference of the 2 pumps and why the outlet cannot come out the side. It must come straight out of the top to clear everything.

Hi Randy, so it seems you solved exactly the same issue I am facing with the mechanical fuel pump. May I get a suggestion on where you had bought the pump that has outlet that goes straight up?
Many thanks!

 

[cdmccul]

Can't see how your block and tackle chain hoist is hanging. Just make sure you have it well supported above.

Also, pull the pin on the engine stand and mount the stand plate (the black part) to the engine first! Then just lift the engine up any random high enough amount and slide the red part of the stand onto the engine. Install the pin, then lower the whole thing onto the wheels.

Remove as much weight from the engine as you can before trying to roll it over... It will be top (or bottom or side) heavy and will fly out of your hands of you don't have a good grip on things.

 

[bobcatzack]

Can't see how your block and tackle chain hoist is hanging. Just make sure you have it well supported above.

Also, pull the pin on the engine stand and mount the stand plate (the black part) to the engine first! Then just lift the engine up any random high enough amount and slide the red part of the stand onto the engine. Install the pin, then lower the whole thing onto the wheels.

Remove as much weight from the engine as you can before trying to roll it over... It will be top (or bottom or side) heavy and will fly out of your hands of you don't have a good grip on things.

Thank you for the valuable advise .. will follow your directions when I get to hoisting the engine to the stand. When you say 'fly out of your hands' do you mean the stand itself might accidentally topple over?

 

[cdmccul]

Thank you for the valuable advise .. will follow your directions when I get to hoisting the engine to the stand. When you say 'fly out of your hands' do you mean the stand itself might accidentally topple over?

Yes. You want to attach the black post onto the back of the engine as close to the center of gravity. If you're taking the head off before flipping it over, you mount it so the big pipe is just above the center of the crank shaft. If you are not pulling the head off, you place it farther above the center of the crank.

ALSO - if you want to take the flywheel off, pull it before you install the mount to the block.

But yea, if you don't watch out, the offset weight of block will quickly pull it out of your hands while tying to roll it over, and most likely topple everything to the ground violently, and will hurt whatever is in the way as it goes down.

 

[bobcatzack]

Yes. You want to attach the black post onto the back of the engine as close to the center of gravity. If you're taking the head off before flipping it over, you mount it so the big pipe is just above the center of the crank shaft. If you are not pulling the head off, you place it farther above the center of the crank.

ALSO - if you want to take the flywheel off, pull it before you install the mount to the block.

But yea, if you don't watch out, the offset weight of block will quickly pull it out of your hands while tying to roll it over, and most likely topple everything to the ground violently, and will hurt whatever is in the way as it goes down.

I do see what you mean. I am trying to avoid more tear down than necessary, so plan to not pull the flywheel. But as you said, will try to center the stand attachment as much as possible to the crankshaft/engine horizontal line.
Thanks!

 

[RandyL]

I do see what you mean. I am trying to avoid more tear down than necessary, so plan to not pull the flywheel. But as you said, will try to center the stand attachment as much as possible to the crankshaft/engine horizontal line.
Thanks!

You do not want your engine stand centered on the crankshaft, that is far too low. The crankshaft is at the very bottom of the engine. Do the best you can to mount the head of the stand above the crank, more inline with the center of weight of the engine. Mine worked out fine as in these photos even though it was still top heavy. I could not get it lower easily. You can imagine how top heavy once the head is put back on. Use a 3-4 ft bar at the end of the stand head to hold or rotate the engine anytime that you pull the locking pin. Rotate it slow and it will be perfect. I will see if I can turn up the info on the fuel pump. I think I have it out in the shop.
I had pulled my flywheel. several reasons.... I don't think my stand would have fit with it on, took a bunch of weight off when handling the block, and it had to come off as I wanted new crackshaft seals in the engine.

 

[RandyL]

I found the info on my fuel pump. It was an ebay purchase. He looked at my photos I sent and confirmed he had what I wanted. It was perfect.

 

[cdmccul]

You do not want your engine stand centered on the crankshaft, that is far too low. The crankshaft is at the very bottom of the engine. Do the best you can to mount the head of the stand above the crank, more inline with the center of weight of the engine. Mine worked out fine as in these photos even though it was still top heavy. I could not get it lower easily. You can imagine how top heavy once the head is put back on. Use a 3-4 ft bar at the end of the stand head to hold or rotate the engine anytime that you pull the locking pin. Rotate it slow and it will be perfect. I will see if I can turn up the info on the fuel pump. I think I have it out in the shop.
I had pulled my flywheel. several reasons.... I don't think my stand would have fit with it on, took a bunch of weight off when handling the block, and it had to come off as I wanted new crackshaft seals in the engine.

You're 100% right there. Didn't mean to convey to center it on the crankshaft but above it. Different definitions of "close" and "a little bit" I guess.

Fuel pump - did he rebuild yours or did you send your core back, etc etc?

 

[bobcatzack]

You do not want your engine stand centered on the crankshaft, that is far too low. The crankshaft is at the very bottom of the engine. Do the best you can to mount the head of the stand above the crank, more inline with the center of weight of the engine. Mine worked out fine as in these photos even though it was still top heavy. I could not get it lower easily. You can imagine how top heavy once the head is put back on. Use a 3-4 ft bar at the end of the stand head to hold or rotate the engine anytime that you pull the locking pin. Rotate it slow and it will be perfect. I will see if I can turn up the info on the fuel pump. I think I have it out in the shop.
I had pulled my flywheel. several reasons.... I don't think my stand would have fit with it on, took a bunch of weight off when handling the block, and it had to come off as I wanted new crackshaft seals in the engine.

Thanks for the clarification Randy .. understood! The close-up pic of your engine on the stand does provide good guidance on which slots to utilize on the engine, for a stable mount.

 

[bobcatzack]

I found the info on my fuel pump. It was an ebay purchase. He looked at my photos I sent and confirmed he had what I wanted. It was perfect.

Great! I believe the same eBay seller has the same pump up for sale as of today .. price is a bit higher than what he charged you .. $90 with shipping (inflation?!)

 

[spitzair]

This is how I mounted my engine when I did the rebuild on it. Seemed very well balanced with it mounted like this...

 

[bobcatzack]

This is how I mounted my engine when I did the rebuild on it. Seemed very well balanced with it mounted like this...

 

[bobcatzack]

Neat! Looks like the mount attachment is from the side of the engine! The stand I bought may not be capable of a side attachment .. will definitely check, thanks!

 

[spitzair]

Yeah I just fabricated a plate that bolts to those 4 holes and then mounted it to my welding table. Worked great and with the table right there I had tons of space to put parts, tools and whatever else mess I made...

 

[RandyL]

You're 100% right there. Didn't mean to convey to center it on the crankshaft but above it. Different definitions of "close" and "a little bit" I guess.

Fuel pump - did he rebuild yours or did you send your core back, etc etc?

The fuel pump was something he had in stock. It was new, not rebuilt.

 

[bobcatzack]

Yeah I just fabricated a plate that bolts to those 4 holes and then mounted it to my welding table. Worked great and with the table right there I had tons of space to put parts, tools and whatever else mess I made...

A quick update on where things stand at this point - I attempted to mount the engine without taking the flywheel off, of course did not work. Also, when trying to remove the 6 flywheel bolts, they are spinning the crankshaft and won't loosen up, so I am kind of stuck. May have to invest in a hammer drill set that can potentially remove the flywheel bolts. Also, at this point, I have the engine laying on the side so I can at least get to oil pan. However, also found that the oil pan would not come out before I remove the flywheel attachment

: (

 

[brdgbldr]

A quick update on where things stand at this point - I attempted to mount the engine without taking the flywheel off, of course did not work. Also, when trying to remove the 6 flywheel bolts, they are spinning the crankshaft and won't loosen up, so I am kind of stuck. May have to invest in a hammer drill set that can potentially remove the flywheel bolts. Also, at this point, I have the engine laying on the side so I can at least get to oil pan. However, also found that the oil pan would not come out before I remove the flywheel attachment

: (

You can try to put a wrench on the pulley side of the crank shaft, with a cheater bar extension braced on the floor, to stop the crank from turning while you loosen the flywheel bolts.

You may have to experiment with the angle used on both wrenches to keep the engine from moving around.