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Mack E7 jake break

Big D 23

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Hey I’m having trouble out of my 2003 Mack E7 jake break. It takes a second or so to kick in then when it does kick on in higher rpms it’s very weak and barely sounds like it’s working till it gets to around 14-15 then it’s sounds good and kicks on stonger 

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If he has Jacob's 690 head, the lash was changed to .021"..  From .017" after a top oil feed update was done and the reset screws in the bridges were replaced with the 'Armoly' screws, and the check valve under the jake head was removed and replaced with the little screw in check valve. If these are not done then lash is .017" ..  even after all of these updates, the engine brake still sucked, just not as bad.  next: If you have "powerleash" you will see the celenoids are clamped directly into the rocker shaft's.  they are sealed by 2 orings and the bail's that hold them in is 'it' usually a bad oring will cause the engine brake to operate all the time, however, it wouldnt hurt to check them, the bottom oring will stay in the hole, so you will have to pick it out. with this engine brake set up, the lash adjustment is different than for the 690 heads. Please post which engine brake you have. I assume Jacob's because of youre issue..  jojo  P.S. correct bridge clearence adjustment and valve adjustment is really important. you may have pinless intake bridges, so no adjustment needed there..

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