Greetings, I'm a new owner of a supposedly lightly used B21 TLB (400 hours) and have recently run into a rash of hydraulic leaks which all seem related to the low pressure oil cooling circuit run off the charge pump. I did not have the tools or smarts to check the pressure in the charge circuit (or high pressure circuits for that matter) before disassembling, but then again I was blowing out oil at both the top of the charge pump and the HST filter at a rate that said "shut this thing down". Looks like I'm not the first owner with this problem as I discovered (under the rubber floor mat) a hole cut in the center frame to provide access to the top of the charge pump/pipe connection for the pipe that runs forward to the oil cooler.
I've dropped the hydraulic reservoir tank and ordered all the replacement O-rings and rubber hoses to preventatively replace when I reinstall. I have the WSM and parts manual which have been invaluable in getting me up to beginner speed on understanding all these hydraulic components which are foreign to me, as most of my previous wrenching experience is on British sports cars. I have a new charge pump to oil cooler pipe, as the old one was deformed at the point of connection on top of the charge pump.
But before I put all this back together and hope the leaks are no more, I wanted to remove and check the components of the Charge Relieve Valve that lives in the body of the HST just below the charge pump. I removed the internal cir-clip and somewhat expected the poppet to pop out under pressure of the spring behind it, but no such luck. I removed the small hex plug and tried some gentle prying on the spring through this hole, but the poppet will not budge.
Any tricks or advice on how to get this poppet, and then the spring and actual valve body out? If it is all gummed up then I may have discovered why I'm blowing those seals on the low pressure circuit, but how can I get the charge relief valve out for a check-up? The stuck poppet is featured in the photo below.
Thanks much,
Steve B of Mosier, Oregon
I've dropped the hydraulic reservoir tank and ordered all the replacement O-rings and rubber hoses to preventatively replace when I reinstall. I have the WSM and parts manual which have been invaluable in getting me up to beginner speed on understanding all these hydraulic components which are foreign to me, as most of my previous wrenching experience is on British sports cars. I have a new charge pump to oil cooler pipe, as the old one was deformed at the point of connection on top of the charge pump.
But before I put all this back together and hope the leaks are no more, I wanted to remove and check the components of the Charge Relieve Valve that lives in the body of the HST just below the charge pump. I removed the internal cir-clip and somewhat expected the poppet to pop out under pressure of the spring behind it, but no such luck. I removed the small hex plug and tried some gentle prying on the spring through this hole, but the poppet will not budge.
Any tricks or advice on how to get this poppet, and then the spring and actual valve body out? If it is all gummed up then I may have discovered why I'm blowing those seals on the low pressure circuit, but how can I get the charge relief valve out for a check-up? The stuck poppet is featured in the photo below.
Thanks much,
Steve B of Mosier, Oregon
