Mndirtguy Posted January 5, 2022 Share Posted January 5, 2022 I recently had a set of Jake's installed on my 2000 e7 460 (didn't have them before) and the Jake's seem weak and also seems not to pull quite as good as before Jake's were installed. Not a huge power difference but seems to be a little. Could something have not gotten set right that these issues are here? Jake's had rebuild kit 4559-31180 installed before putting on my truck. Quote Link to comment https://www.bigmacktrucks.com/topic/69023-2000-e7-460-weak-jake-brake/ Share on other sites More sharing options...
theakerstwo Posted January 5, 2022 Share Posted January 5, 2022 (edited) dont expect much from them.I have always said on a mack you have as much braking power if you roll the windows up on both doors and open them.But if you have power lost then get some one to go back thru the over head. Edited January 5, 2022 by theakerstwo 1 Quote glenn akers Link to comment https://www.bigmacktrucks.com/topic/69023-2000-e7-460-weak-jake-brake/#findComment-486563 Share on other sites More sharing options...
Mndirtguy Posted January 5, 2022 Author Share Posted January 5, 2022 Thanks Quote Link to comment https://www.bigmacktrucks.com/topic/69023-2000-e7-460-weak-jake-brake/#findComment-486569 Share on other sites More sharing options...
Joey Mack Posted January 5, 2022 Share Posted January 5, 2022 (edited) Do you know if the Armolly reset screw kit p/n 215SB321 was installed? if so, the engine brake lash is .021". and like Glenn said, check the valve adjustment again.. .016" int. .024" exh.. jojo Edited January 5, 2022 by Joey Mack More content needed 1 Quote Link to comment https://www.bigmacktrucks.com/topic/69023-2000-e7-460-weak-jake-brake/#findComment-486570 Share on other sites More sharing options...
Joey Mack Posted January 5, 2022 Share Posted January 5, 2022 before I forget.. the bridges need to be set to .010" on each end using 2 feeler gauges. the drag needs to be equal for proper valve opening timing as well as keeping a side load off of the bridge pins.. jojo 1 Quote Link to comment https://www.bigmacktrucks.com/topic/69023-2000-e7-460-weak-jake-brake/#findComment-486571 Share on other sites More sharing options...
Mndirtguy Posted January 6, 2022 Author Share Posted January 6, 2022 Thanks Joey mack Quote Link to comment https://www.bigmacktrucks.com/topic/69023-2000-e7-460-weak-jake-brake/#findComment-486592 Share on other sites More sharing options...
Joey Mack Posted January 6, 2022 Share Posted January 6, 2022 👍 Quote Link to comment https://www.bigmacktrucks.com/topic/69023-2000-e7-460-weak-jake-brake/#findComment-486593 Share on other sites More sharing options...
Hans Remmers Posted January 6, 2022 Share Posted January 6, 2022 The E-tech's I've seen lost braking power as the engine oil warmed up when the engine got some miles on it. There was an update that used external oil lines up to the Jakes on those engines and they worked very well. 1 Quote Link to comment https://www.bigmacktrucks.com/topic/69023-2000-e7-460-weak-jake-brake/#findComment-486595 Share on other sites More sharing options...
Joey Mack Posted January 6, 2022 Share Posted January 6, 2022 I wonder if anyone near him has the jig to drill the Jake head, and heck, the knowledge to do it? I dont have access to search out the service bulliten from 20 years ago... jojo 1 Quote Link to comment https://www.bigmacktrucks.com/topic/69023-2000-e7-460-weak-jake-brake/#findComment-486596 Share on other sites More sharing options...
Hans Remmers Posted January 6, 2022 Share Posted January 6, 2022 1 minute ago, Joey Mack said: I wonder if anyone near him has the jig to drill the Jake head, and heck, the knowledge to do it? I dont have access to search out the service bulliten from 20 years ago... jojo I remember hearing about the bulletin years ago and have since ran a 2000 460 and it worked extremely well. If the engine is a 460 I would think it'd have to be an E-tech and don't know that a regular e7 Jake would even work on that engine. Quote Link to comment https://www.bigmacktrucks.com/topic/69023-2000-e7-460-weak-jake-brake/#findComment-486597 Share on other sites More sharing options...
Joey Mack Posted January 6, 2022 Share Posted January 6, 2022 the Jake on yours is a 690 series, E-7's had a 680 series, the top oil feed SB did help the performance, but it was still a lame E.B. compared to other engine makes. I remember test driving the trucks for weak Jake performance and having to fill out a report on oil pressure and engine speed, blah, blah, blah.... and then we would do a top oil feed conversion.. it was a very care filled job to drill the Jake head 'once' without busting through or missing the oil gallery.. anyway, maybe some one will post the bulliten, basically for entertainment purpose's jojo 1 Quote Link to comment https://www.bigmacktrucks.com/topic/69023-2000-e7-460-weak-jake-brake/#findComment-486598 Share on other sites More sharing options...
Swishy Posted January 6, 2022 Share Posted January 6, 2022 What we do to check Engine Brake in a ruff way <1> Get truck temp upto operating temp ( go for a drive ) <2> Use the EB to get the oil circulatin <3> Put cog box in gear U normally start off in (for us 5th) <4> Drive flat out in th@ take off gear (5th) upto the gov speed 2000rpm <5> back off to bring on engine brake n see how much it pulls U up the higher the gear the less retardation or ruffly much the same as pulling power to increase revs cya Quote Link to comment https://www.bigmacktrucks.com/topic/69023-2000-e7-460-weak-jake-brake/#findComment-486600 Share on other sites More sharing options...
Onyx610 Posted January 6, 2022 Share Posted January 6, 2022 sb266015.pdf Quote Link to comment https://www.bigmacktrucks.com/topic/69023-2000-e7-460-weak-jake-brake/#findComment-486606 Share on other sites More sharing options...
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