We have had a problem with blown head gaskets on our 621s and 627s. they are mid 70's models. Have always followed the install proc. and correct torqe specs. only in the past have reused old head bolts because of orders from old boss.Has anyone else had this problem w/3406 cat eng.s? or is there any sugestions to prevent this happening?
Hi , Brad have you been checking Cylinder liner projection? if your having repeat failures that would be good reason if you liners are low
What PAcattech said! Checking liner projection is the second most important thing you can do, aside from making sure all surfaces are clean and straight. (head warp etc.) We have reused head bolts with great success on our machines. The only bolts that get changed every time are exhaust manifold studs, weak design and very subject to rusting out.
According the Service Literature head bolts, although they are tightened using a torque-turn procedure, are infinitely re-usable provided they meet reusability guidelines. Normally torque-turn bolts are one life only, head bolts are an exception.
So Cat doesn't provide a length gauge for head bolts like Cummins does? As I recall there used to be a spec for the older engine head bolts. Is that not so anymore?
I know this isnt a 3406, but I just bought a truck with a Cat C12 engine, water in oil We pulled the head and sent it to the shop, the head was wrapped, so they rebuilt the head and machined the surface. The head gasket didnt show signs of leaking, but the head was wrapped bad. I really think someone ran the engine hot I called Cat and they said they had a re-torquing method on that engine, the old torque method, was not correct They also said the head bolts on my engine had to be replaced, because they would stretch. Bolts and washers around $250, head gasket set $500, when it comes to this stuff I use all Cat stuff Are you getting water in the oil or?
thanks guys, will check projection and will have head checked for warpage.have new head bolts and gasket kit, starting today on project. will advize on findings. thanks again, B
We also have C12 engs in our trucks, never heard of diff. torqe specs. will investagat thanks willis
According to SIS-web on a C-12 the head bolts MUST be replaced every time the head comes off. Additionally I found this gem ........... "If the engine is equipped with a compression brake, then also install new head bolt studs." This is also interesting, it dates from 2007 so most likely will not apply to more recent engines ................. "Caterpillar has released a new cylinder head, a new cylinder block, a new cylinder head gasket, and a new camshaft follower for the C-10 and C-12 production engines. Caterpillar recommends reading and understanding this procedure completely before attempting any of the replacements that are described. The following is a list of possible replacement components for the cylinder block and cylinder head: 200-2055 Cylinder Block 200-2054 Cylinder Block 162-0681 Cylinder Block 179-9461 Cylinder Head 162-0683 Cylinder Head If you have any of the components that are listed above, you need to use the 187-3307 Cylinder Head Gasket . Cylinder Head Gasket. The new 187-3307 Cylinder Head Gasket replaces the 187-3306 Cylinder Head Gasket in all current production engines. The new 187-3307 must be used in any combination of the following components: 200-2055 Cylinder Block 200-2054 Cylinder Block 162-0681 Cylinder Block 179-9461 Cylinder Head 162-0683 Cylinder Head The former gasket 187-3306 Cylinder Head Gasket must still be used with all 1YN, 2PN, 9NS1-16227, 8YS1-05399, 2KS1-00388, and 3CS1-00718 engines. Cylinder Head Assembly. The new 179-9461 Cylinder Head includes the cylinder head, cylinder head plugs, valve guides, and valve seat inserts. Cylinder Head Group. The new 148-2144 Cylinder Head Gp is a complete cylinder head assembly without the unit injectors and without the rocker arms. Cylinder Block Assembly. The new 200-2054 Cylinder Block is a complete cylinder block without cylinder liners and without piston assemblies. Bracket Assembly. There are two new bracket assemblies. The new 148-2064 Bracket As for the camshaft followers will replace the former 129-2884 Bracket As . The new 148-2065 Bracket As will replace the former 129-2882 Bracket As . Use the 148-2063 Valve Lifter Group with the new brackets for the camshaft follower. Note: The old 129-2884 Bracket As for the camshaft follower can not be used with the 162-0681 Cylinder Block . The new 148-2064 Bracket As for the camshaft follower can not be used with the old 128-0406 Cylinder Block. Torque procedure is: - 1. Tighten bolt (1) through bolt (26) in a numerical sequence to a torque of 160 ± 15 N·m (120 ± 11 lb ft). 2. Tighten bolt (1) through bolt (26) again in a numerical sequence to a torque of 160 ± 15 N·m (120 ± 11 lb ft). 3. Place an index mark on each bolt head. Turn bolt (1) through bolt (26) in a numerical sequence for an additional 90 degrees (1/4 turn). 4. Loosen bolt (1) through bolt (26) until the washers are loose under the bolt heads. 5. Repeat Steps 1-3. 6. Tighten bolt (27) through bolt (33) in a numerical sequence to a torque of 28 ± 7 N·m (20 ± 5 lb ft). 7. Install the head bolt spacers on the three head bolt studs. Tighten the three head bolt studs to a torque of 100 ± 20 N·m (75 ± 15 lb ft). On all engines where cylinder head bolts can be re-used (not C-10, C-12 obviously) there is a re-usability guideline that basically states that the bolt can be re-used provided that: - 1. The head is not damaged, chipped or corroded. 2. The washer face under the head is flat & free from burrs, corrosion, & pitting, and the radius between the head and the shank is smooth. 3. The shank is straight, shows no sign of bending or neckjing, and is not corroded or pitted. 4. The threads are in good condition, and free from deformation, stripping, etc.