fjh Posted June 9 Share Posted June 9 9 minutes ago, longshipconstruction said: Reviving my old thread for model 690 jake. I purchased the Jacob’s kit from Mack for almost $1400 with 2 new solenoids. Was told I got the “last kit in the USA” and they are out of production. My question is, am I missing something between the rocker assembly and the jake head for oil delivery? The 2 pictures are when I removed the Jake head, and nothing else. Doesn’t look like there is any o-ring or anything to seal it. There is also an open hole on the bottom of the jake head that looks like it’s missing something. (Shown in the first image to the far right) Any help is appreciated! That funny screw replaced a spring and ball that came originally!just clean everything up and replace everything as best you can! Blow everything out as well with compressed air! Quote Link to comment https://www.bigmacktrucks.com/topic/62942-e7-460-jake-brake-oil-pressure-loss/page/2/#findComment-553322 Share on other sites More sharing options...
Joey Mack Posted June 9 Share Posted June 9 you are not missing anything for the bore in the jake head.. the spring check ball and rings was deleted.. you are fine !! Quote Link to comment https://www.bigmacktrucks.com/topic/62942-e7-460-jake-brake-oil-pressure-loss/page/2/#findComment-553323 Share on other sites More sharing options...
Joey Mack Posted June 9 Share Posted June 9 the lash on the Jake piston is .017'' but if you have the 215SB321 kit installed you can set the lash to .021... When I worked at Maine Mack in Portland, I bet I did 50+ updates. does yours have the top oil feed update ? Quote Link to comment https://www.bigmacktrucks.com/topic/62942-e7-460-jake-brake-oil-pressure-loss/page/2/#findComment-553324 Share on other sites More sharing options...
longshipconstruction Posted June 9 Author Share Posted June 9 Thank you fjh and Joey Mack. Mine does not have the upper feed, yet… but I do buy my parts from Portland now. This is the kit I got, I’m not seeing the pn you referenced, but it may now be a dirty Volvo number now. So far during disassembly I haven’t found a smoking gun, but some orings look pretty trashed. Only other thought I had was making sure the holes in the accumulator bore are not supposed to be plugged? Also I haven’t backed the slaves off in the picture, looks like an awful lot of adjustment left. Like they might have been way off? id settle for a weak jake, I’ve never had them function whatsoever in 4 years. Really appreciate the feedback! 1 Quote Link to comment https://www.bigmacktrucks.com/topic/62942-e7-460-jake-brake-oil-pressure-loss/page/2/#findComment-553326 Share on other sites More sharing options...
longshipconstruction Posted June 9 Author Share Posted June 9 Think I found my smoking gun. control valves are all totaled. 1 1 Quote Link to comment https://www.bigmacktrucks.com/topic/62942-e7-460-jake-brake-oil-pressure-loss/page/2/#findComment-553327 Share on other sites More sharing options...
The Heinz Posted June 10 Share Posted June 10 The 690 model being discontinued is absolutely true, and you can thank Volvo for that. Jacobs told me outright it was Volvo that produced them, and now obsoleted them without a backup. This topic is exactly what brought me to this forum in the first place, we had a 2000 RD that had top end damage thanks to someone not torqueing the rocker shaft correctly, ruining the head and the jakes. The customer ended up buying a used one from somewhere and sending it in. 2 Quote Link to comment https://www.bigmacktrucks.com/topic/62942-e7-460-jake-brake-oil-pressure-loss/page/2/#findComment-553400 Share on other sites More sharing options...
Joey Mack Posted June 10 Share Posted June 10 I have a bunch of old parts i saved from 690 heads. If you cant find what you need, post it with pics and i will see what i have 1 Quote Link to comment https://www.bigmacktrucks.com/topic/62942-e7-460-jake-brake-oil-pressure-loss/page/2/#findComment-553401 Share on other sites More sharing options...
Popular Post longshipconstruction Posted June 10 Author Popular Post Share Posted June 10 Thank you all for the help! Jakes are working very well now, even hot without fade. Truck has 47,000 hrs on the clock so I wasn’t optimistic this was all it needed, but I am very pleasantly surprised. Again, thank you for the responses. This forum has been a valuable resource for me, and I really appreciate it! 3 Quote Link to comment https://www.bigmacktrucks.com/topic/62942-e7-460-jake-brake-oil-pressure-loss/page/2/#findComment-553415 Share on other sites More sharing options...
fjh Posted June 10 Share Posted June 10 26 minutes ago, longshipconstruction said: Thank you all for the help! Jakes are working very well now, even hot without fade. Truck has 47,000 hrs on the clock so I wasn’t optimistic this was all it needed, but I am very pleasantly surprised. Again, thank you for the responses. This forum has been a valuable resource for me, and I really appreciate it! Yup spread the word! Thanks to Barry and Watts for making it happen! 1 Quote Link to comment https://www.bigmacktrucks.com/topic/62942-e7-460-jake-brake-oil-pressure-loss/page/2/#findComment-553419 Share on other sites More sharing options...
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