# Left brake will not hold pressure



## lanerlg777 (Jul 20, 2013)

I have a IH 484 (1980), I replaced the brake piston O-ring and still can not get brake pressure to hold. I have all the air out of the line. I can get some petal pressure but it will not hold. Before I replaced the O-ring I couldn't get any pressure so I know the new O-ring is helping. Can anyone give me some suggestions on what else to do.
Thanks


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## cyrush (Apr 20, 2010)

Did you replace all 3 o rings per side?? 2 on brake piston and 1 behind the diff bearing carrier??


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## etemplet (May 6, 2012)

Perhaps you need to replace the master cylinder on the left side. I have a lot of pictures of the break system on my backhoe if it is the same set up. I found some master cylinder kits. Look for posts under my signature. I have a lot of info on the site about the 3400A BAckhoe.


How difficult was it to replace the o-ring ? I am sure I have some leakage in there. Any pictures of the take apart ??


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## lanerlg777 (Jul 20, 2013)

It wasn't to hard to put the o-ring in the piston. It took a lot time to remove the fender, fuel tank and axle not mentioning the re-installation. The master cylinder might be my problem all the time. I have no leakage within the axle. IH service guy is the one that told me the o-ring needed to be replaced. Thanks for your help.


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## etemplet (May 6, 2012)

Don't buy a master cylinder unless you have too. I have extensive pictures of the master cylinder process posted on this site. I also have part numbers and where you can buy the rebuild kits. $35.00 as opposed to $200+ for a new MC. It took me a while to find that place but I saved all of the information. Good Luck.

I have a lot of pictures in this thread of different parts and the brake components under the dash are pretty extensive. here ya go ! There are screens in the feed lines for the brakes. Check those out as well.


http://www.tractorforum.com/f192/international-3400a-progress-21200/


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## lanerlg777 (Jul 20, 2013)

Sounds good too me! I just got out of the hospital with a hip replacement. As soon as I'm able I will get back in touch with you and get the part numbers and order. Thanks a million.


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