Got the head and everything back on yesterday. Setting the valves was not fun, but I did it. Cracked the fuel lines at the injectors and had it going it just a few minutes. I read somewhere to run it a little while, take the valve cover and glow plug bar off and retighten the head bolts…..is that necessary? I filled it with distilled water which I will drain and replace with antifreeze after I run it a while. What about those head bolts? Banjo
RTV 900 Head Gasket
- Thread starter texczech
- Start date
“I read somewhere…”. I read a Lot of stuff…”somewhere”… which does not make it reliable information.
It is almost Always recommended to “re-torque” wheel lugnuts/lugbolts shortly after driving the vehicle some distance… but I have Never found any discrepancy if the proper torque was applied the First Time.
Once a specified torque is applied….. the fastener-friction must be overcome to achieve Any movement of the fastener afterward…. and that would be and OVER-torque condition, in my view. However, if you run that engine and then check the torque and find a loose fastener AT the previously specified torque… then there has been a fastener failure. I suppose that COULD happen…. but not likely.
I would not disassemble it again just to check torque which I Knew to be correct previously. YMMV
It is almost Always recommended to “re-torque” wheel lugnuts/lugbolts shortly after driving the vehicle some distance… but I have Never found any discrepancy if the proper torque was applied the First Time.
Once a specified torque is applied….. the fastener-friction must be overcome to achieve Any movement of the fastener afterward…. and that would be and OVER-torque condition, in my view. However, if you run that engine and then check the torque and find a loose fastener AT the previously specified torque… then there has been a fastener failure. I suppose that COULD happen…. but not likely.
I would not disassemble it again just to check torque which I Knew to be correct previously. YMMV
When I replaced the head on the 2005 I rechecked the bolts and found only one that needed additional torque. I thought I may have not torqued it right the first time. Pays to double check.
Junkman
Administrator
Retorquing head bolts has been a procedure for many decades with standard bolts. The reasoning behind it is that sometimes there might be a rough spot on the threads of the bolt or in the block that will allow you to reach the predetermined torque value however the head of the bolt isn't set to that torque against the top of the hole. With the engine going through a couple of heat and cooling cycles the normal stretching of the steel will even out the torque. Occasionally you will find one or two fasteners that will need that extra torquing. Today newer engines don't have this requirement since the head bolts are only torqued once and they are designed to stretch at maximum torque and the stretch resembles a spring-like elasticity of the fastener. . For this reason, those bolts are never reused, and new bolts are needed every time a head is removed.
In the old days, we would use a beam torque wrench and had to watch the pointer to know when the torque value was achieved. Today more modern torque wrenches are click type and will give a click when they reach the set value. The most modern torque wrenches that have come out in the last couple of years are electronic and will give an audible warning when the torque value is reached. I have seen some that will record the values attained and display them on an electronic display on the wrench.
In the old days, we would use a beam torque wrench and had to watch the pointer to know when the torque value was achieved. Today more modern torque wrenches are click type and will give a click when they reach the set value. The most modern torque wrenches that have come out in the last couple of years are electronic and will give an audible warning when the torque value is reached. I have seen some that will record the values attained and display them on an electronic display on the wrench.
Regardless of what type torque-wrench is used….the TECHNIQUE of its use is Paramount for accuracy.
Whenever I go to the Tire Store I was those guys dutifully grab a torque-wrench and set the “clicker” on the specified torque for that particular vehicle….. then they “lunge” upon the wrench which certainly gives them a “satisfying CLICK”….. but unfortunately they actually OVER-Torque the fasteners because of their “lunging-technique” which forces the wrench further even AFTER the click is obtained. If the wrench is set to 110 ft lbs…. they are likely applying 140 or More …. in actuality the amount being an Unknown. This may not be critical in a tire installation because the recommended torque is a “minimum” requirement…. But in most other situations the recommended-torque falls within a “range”…and that range cannot be assured without proper, educated use of the tool
If an extension is used along with a deep socket…. if the extension/socket combo is not supported with one hand …to prevent lateral application of force upon the socket/fastener….while the other applies the torque in an evenly-applied movement…stopping the Moment the ”specified torque” is obtained……. then increased fastener friction due to the momentarily-mis-aligned extension/socket/fastener occurs. This likely results in an UNDER-Torque condition.
Whenever I go to the Tire Store I was those guys dutifully grab a torque-wrench and set the “clicker” on the specified torque for that particular vehicle….. then they “lunge” upon the wrench which certainly gives them a “satisfying CLICK”….. but unfortunately they actually OVER-Torque the fasteners because of their “lunging-technique” which forces the wrench further even AFTER the click is obtained. If the wrench is set to 110 ft lbs…. they are likely applying 140 or More …. in actuality the amount being an Unknown. This may not be critical in a tire installation because the recommended torque is a “minimum” requirement…. But in most other situations the recommended-torque falls within a “range”…and that range cannot be assured without proper, educated use of the tool
If an extension is used along with a deep socket…. if the extension/socket combo is not supported with one hand …to prevent lateral application of force upon the socket/fastener….while the other applies the torque in an evenly-applied movement…stopping the Moment the ”specified torque” is obtained……. then increased fastener friction due to the momentarily-mis-aligned extension/socket/fastener occurs. This likely results in an UNDER-Torque condition.
scottybilt
Member
OK guys,can we get back to head gasket replacement and stop the BS.......this is a great thread and alot of us that have d902 really helps,...btw banjo did you get your machine up and running?
”talked down to”… Really? You can’t see the corollary…?
Sorry…. DIdn’t mean to try to help you…
Yes… Ran it a good bit today. Got it over near the hot zone….fan comes on and temp drops…will recheck head bolts…& .check valves. I called and ordered a new top and bottom radiator hose and new clamps from local Kubota dealer and hope for another 2000 hours out of it. Already replaced the other hoses. If anyone has one of these older machines, it would be a good idea to replace the water hoses before they start to leak. Keep the D902 cool and no telling how long it will last. The work shop manual is a free download if anyone wants to look for it but it’s about 400 pages for the whole thing. Banjo
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