Jump to content

Mack E7 jake break


 Share

Recommended Posts

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 

Link to comment
Share on other sites

I have a 350-HP 2001  RD when new had the same the dealer were putting " oversized " bearing to increase oil pressure ......then corporate say's we have a fix a new oil pump so mine was the fix before the external line's  in other area's work well after ?

 

Ed

Link to comment
Share on other sites

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..

  • Like 1
Link to comment
Share on other sites

Here is the part number for the top oil feed system.. the drilling procedure is VERY IMPORTANT.  if you 'miss', the Jake head is junk..  Jojo

KIMG0870.JPG

  • Like 2
Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

 Share

  • Recently Browsing   0 members

    • No registered users viewing this page.
×
×
  • Create New...