Archived low vac reserve hard pedal,brakes

[Timgibson]

im trying to diaq a 1994 ram diesel ,the pedal gets like a rock after a couple of applications,the only test in shop manuel is for how much vac pump makes,it passes that test but i feel it doesnt have enough volume/i suspect pump is not able to recover fast enough but would like to check further. all hoses and connections are new as well as booster and master,any help is apprecated

 

[illflem]

If it happening at idle it's normal. The vacuum pump just doesn't put out enough unless the rpms are up.

 

[Deezul1]

An auxillary vacum tank can be added to increase the vacum reserve and help low speed braking.

 

[ToolManTimTaylor]

Aso Dbl Check for dryrot on ANY lines or seals You may not see em but they may exist.

 

[Andy Redmond]

I second what tool man says. Most of our trucks make about the same vacuum at idle as rated rpm (is your idle at least 800)



Did you get 20-25 inches of vacuum at the pump?



Look at the 1/8 and 3/16" lines where they attach to the firewall above the booster, particularly the soft rubber connectors, also see that the check valve on the brake booster is working? . . air should only travel one way.



There should be a tiny reservoir box on the driver's side inner fender directly adjacent to the master cylinder. If you have abs/4whl abs then it may be under neath and difficult to see, it has a 1/4-3/8 vac. line that is hose clamped to the top of it.



You could plumb into this to add a second reservoir for "reserve. "



Good luck

Andy

 

[Timgibson]

update on brake problem

i installed a extra vac tank and this has fixed the problem. i still feel the vac pump is not able to produce the volume it once could-) :--. :--) :-{} :-{}

 

[wcjp]

I used small zip ties at every vacuum connection. This helped alot. I don't feel it's perfect yet. I still need to add an aditional reservoir. However, I can actually still feel normal brakes the next morning.