Noble1 Posted April 22, 2023 Share Posted April 22, 2023 Doing some exhaust work and found this valve? Is it an exhaust brake? should we fix it or remove it? It’s fozen now Quote Link to comment https://www.bigmacktrucks.com/topic/72762-what-is-this-valve-97-ch-454/ Share on other sites More sharing options...
Hans Remmers Posted April 22, 2023 Share Posted April 22, 2023 I'd say it once was an exhaust brake and if the truck has an engine brake I'd definitely get rid of it. Otherwise how much time and money do you want to spend trying to fix it? It looks like it's in a difficult to access location too. Quote Link to comment https://www.bigmacktrucks.com/topic/72762-what-is-this-valve-97-ch-454/#findComment-529727 Share on other sites More sharing options...
Mark T Posted April 22, 2023 Share Posted April 22, 2023 Yes, that's an old Stealth Brake . (exhaust brake) . Probably not worth trying to repair at this point. Quote Link to comment https://www.bigmacktrucks.com/topic/72762-what-is-this-valve-97-ch-454/#findComment-529728 Share on other sites More sharing options...
mechohaulic Posted April 22, 2023 Share Posted April 22, 2023 not leaking . just leave it . takes up the gap. my hino had similar set up. Quote Link to comment https://www.bigmacktrucks.com/topic/72762-what-is-this-valve-97-ch-454/#findComment-529733 Share on other sites More sharing options...
Joey Mack Posted April 22, 2023 Share Posted April 22, 2023 Stealth Brake.. 1 Quote Link to comment https://www.bigmacktrucks.com/topic/72762-what-is-this-valve-97-ch-454/#findComment-529740 Share on other sites More sharing options...
mrsmackpaul Posted April 22, 2023 Share Posted April 22, 2023 If it was mine, I would free it up and get it working I don't believe you can ever have to much braking Paul Quote Link to comment https://www.bigmacktrucks.com/topic/72762-what-is-this-valve-97-ch-454/#findComment-529750 Share on other sites More sharing options...
Mark T Posted April 23, 2023 Share Posted April 23, 2023 2 hours ago, mrsmackpaul said: If it was mine, I would free it up and get it working I don't believe you can ever have to much braking Paul They weren't very effective. Better chance of one of those damaging the turbo , than adding much stopping power. All they really did was preload the valve so the Jake could bump it open a little later ( bigger lash ) . Not very effective on an E7. 1 Quote Link to comment https://www.bigmacktrucks.com/topic/72762-what-is-this-valve-97-ch-454/#findComment-529759 Share on other sites More sharing options...
fjh Posted April 23, 2023 Share Posted April 23, 2023 14 hours ago, Mark T said: They weren't very effective. Better chance of one of those damaging the turbo , than adding much stopping power. All they really did was preload the valve so the Jake could bump it open a little later ( bigger lash ) . Not very effective on an E7. Amen to this ! We had a customer running from here to California He took out countless turbos! The back pressure on long grades would push into the base of the engine and he would be followed by a huge cloud of steam from the draft tube! Un fortunately I would leave well enough alone! This operated off stage 2 of the switch on the dash! Quote Link to comment https://www.bigmacktrucks.com/topic/72762-what-is-this-valve-97-ch-454/#findComment-529813 Share on other sites More sharing options...
mechohaulic Posted April 23, 2023 Share Posted April 23, 2023 trying to free it up for very little gain on braking could result in cracking the casting , now you end up looking for a spacer to take the gap in system. not leaking ;let it be. as earlier stated on my hino FA exhaust brake worked well , not holding back 80K cross country either. Quote Link to comment https://www.bigmacktrucks.com/topic/72762-what-is-this-valve-97-ch-454/#findComment-529815 Share on other sites More sharing options...
mrsmackpaul Posted April 23, 2023 Share Posted April 23, 2023 3 hours ago, fjh said: Amen to this ! We had a customer running from here to California He took out countless turbos! The back pressure on long grades would push into the base of the engine and he would be followed by a huge cloud of steam from the draft tube! Un fortunately I would leave well enough alone! This operated off stage 2 of the switch on the dash! How do they damage the turbo ? Not been a smart ass, I thought once the pressure was up a bit the butterfly was pushed open by the exhaust, maybe when they start to seize up I know the guillotine type added a lot of pressure and heavier exhaust valves were needed to stop valves floating I have never heard of issues with the butterfly types that are used on Japanese and European trucks Paul Quote Link to comment https://www.bigmacktrucks.com/topic/72762-what-is-this-valve-97-ch-454/#findComment-529820 Share on other sites More sharing options...
Mark T Posted April 23, 2023 Share Posted April 23, 2023 They used to destroy the seal in the turbo. Then the exhaust gasses would be going through the oil return into the crank case. It was an issue with them, maybe poor combination of turbo and exhaust brake compared to others ??? There was even a test of putting the turbo's oil return into a bucket and looking for bubbles. Then if you had one, the lash on the Jake itself was set larger (like an extra twenty five thousands or something like that) so without readjusting that lash without the exhaust brake part, the Jake itself could develop issues. They just weren't the best mousetrap. 1 Quote Link to comment https://www.bigmacktrucks.com/topic/72762-what-is-this-valve-97-ch-454/#findComment-529826 Share on other sites More sharing options...
fjh Posted April 23, 2023 Share Posted April 23, 2023 Paul ! We have done the same test on turbos with out the brake! If you have an engine with excessive blow by it pays to do this test ! Standard turbos and VGT turbos can screw up to! It was quite a chronic thing with stealth thou! The valve springs were different on these I installed one once and the valve springs had be changed as well as what MT is saying there! Quote Link to comment https://www.bigmacktrucks.com/topic/72762-what-is-this-valve-97-ch-454/#findComment-529833 Share on other sites More sharing options...
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