2012 Prius - The Good Ol' P0301 Gremlin!!!

The replacement head bolts in my order are indeed for a no. 12 Triplesquare.



Gasket Master's video shows at 18:51 that they are no. 12 Triplesquare. saneauto's video also indicates they are no. 12's as well. Though he calls them simply "M12's" from his experience working on VW's. 97.7779% sure it is a no. 12 Triplesquare at this point. Harbor Freight didn't have them, but Autozone did for $22. In any case, they aren't sold individually, they are bought as a 4pc set. The set has a no. 10 Triplesquare too. If adding up the math, the points on the bolt pattern are the same. A double hex would have 12 points. Three squares (or triple squares) would also have 12 points. Might just be a semantics thing (double-hex, Triplesquare, Mxx) and there may be a misprint in the manual on the sizing. Highly unlikely it is a no. 10. Why??? Because the no. 10 in the set is for a 3/8" socket. The no. 12 is 1/2". No way a ratchet driver for head bolts would use a 3/8" drive.

When I do get there, I'll find out for sure and confirm.

Regarding the RTV, I know which type are needed. It is just a matter of already having enough of a left over quantity in my tool box from my Ford Ranger HG repair or having to go pick some up.

 

Yikes, 140 ft lbs! Need to make sure I have long sleeves and thick gloves for that one.

 

I went ahead and swooped up CTA Tools 9295 from Amazon.

I am checking the fitment right now with the replacement head bolts with the Triplesquare however, I can't see how it is going to add much error in this instance. It is quite snug. Will see how it goes with the bi-hex when they get here.

 

Double post.

 

Thanks! I hadn't seen these videos yet. I learned another little nugget from these videos. The head gasket bolts washers are directional. Who would have thought!

 

Getting it off doesn't concern me as I have a Ridgid 18volt 1/2" impact wrench. Should be enough to do the job. It is getting it back on to proper torque spec. Doing it from the engine compartment side is going to be tight and sure to be a a knuckle shredding proposition. I can always do it from the wheel well side with an extension. Torque spec will be off a bit in doing so. Or do it like any mechanic would do (wing it) with just an impact wrench.

But heck, it is a Toyota and beats the heck out of working on my Ford Ranger truck.

I have it scoped out as a 3 day job.

1. Day 1 - Tear down, clean removed parts
2. Day 2 - Continue tear down if needed, let some parts soak in cleaning fluid over night
   
3. Day 3 - Reassembly

I wouldn't call Gasket Master's hacks. You aren't going to find any mechanics better at doing this. They aren't any different than any mechanic other than that they specialize in one type of repair. If you take it to any non-dealer mechanic, they'll just clean the mating surfaces and be done with it. If you want your cylinder block thoroughly cleaned, they'll charge you for their time. Then the cost for the repair goes from the $1550 that Gasket Master's charges to $2500 and up. It will reach the point where the cost of repair isn't worth continued ownership of the vehicle. Then a mechanic won't get the car owner's business. If you take it to a dealer, they are going to replace parts and charge you for them, not clean them and you'll pay a whole lot more.

$1550 that Gasket Masters charges isn't a whole lot of money. And if anyone could easily use their services, it would be me since I am in the same town they are in. But I want the extra mile stuff which will add another $1500 to the repair cost: use genuine coolant, keep rockers in sequence, use OEM parts, pull oil pan to get rid of sludge, trickle charge aux battery, soak EGR cooler in Purple Power and power wash, etc. That is why I am doing it myself. And who is to know if my OCD-ness shall produce results that matches Gasket Masters' experience? I am betting it will though.

Yeah, I left out the word "washer". Edited my post above. Of course the bolts are directional. When it get to this part, I'll move the bolts and washers pulled out of the engine to the work bench and put the washers on the new head bolts in the proper direction. I am looking at the new head bolts and there is some debris/metal shavings in the sockets and a bit on the threads. They should all be cleaned with a quick spray of break clean before assembly as those shaving would definitely get into the engine. Then drop the new head bolts and washers in an oil bath to ready them for assembly a day or two later. Being sure to discard the used head bolts as I go to not get them mixed up.

I am updating my task list now and will post the finalized steps when done.

I'll just remove the aux battery and use the opportunity to put the battery on the trickle charger for a few days. Doing so eliminates that potential for the back feed issue he speaks of and accomplishes the same thing.

 

Amazon delivered CTA Tools 9295 today. The no.10 bi-hex is definitely the proper socket.



I have both of them here in front of me now. The tolerance play is about the same. If you have the no. 12 Triplesquare already, there probably isn't a need to get the #10 double-hex unless you want to use the proper tool. The no.12 Triplesquare is known to work for this application. If you don't have either, then be sure to get the proper one. I am returning the Triplesquare set to Autozone.

 

Dobrowski's Garage's video linked earlier by @Paul E. Highway is a must see if you are going to tackle head gasket repair. Of the ones I have seen, none touch upon how to re-engage the timing tensionor during re-installation. Dobrowski addresses how to properly set the timing and added a nugget of wizardry on how to prevent timing from jumping upon re-installation.

This is the big week. Tackling this job on Thursday when I'll have no rain for 3 straight days (fingers crossed). All tools have been acquired, baggies for bolts and nuts have been labeled, replacement fluids are in place, wires have been labeled with tape, power tools are charged up, torque sequences & specs have all been printed out, all the required tools have been laid out. Pretty much all the laymen things that have to be done to ensure time isn't wasted on this hopefully one-time job.