Birty Dastards Jeep Club

Tech Forum => Workshop => Topic started by: willo on September 01, 2012, 09:02:40 PM

Title: tj question
Post by: willo on September 01, 2012, 09:02:40 PM
would the amp draw from the barke servo when foot is on pedal be enough to stall the car if the battery was a bit suspect?
Title: Re: tj question
Post by: Panic mechanic! on September 01, 2012, 09:06:37 PM
no.but you can stall an engine by repeatedly pumping the brake pedal very quickly.

or is the brake servo diaphram split so when you apply it its leaning the fuel out too much?
Title: Re: tj question
Post by: willo on September 01, 2012, 09:11:26 PM

or is the brake servo diaphram split so when you apply it its leaning the fuel out too much?

ok I may need a brief lesson in how they work

could the diaphram split if left stood for a while?
Title: Re: tj question
Post by: isle of man on September 01, 2012, 09:14:01 PM
If the diaphram is fooked the pedal would be on Prozac!!!
Title: Re: tj question
Post by: Cockney Boy on September 01, 2012, 09:17:25 PM
It could be either by a blockage of the vacuum hose or a cracked, ruptured or leaking diaphragm. Another is the master cylinder leaking brake fluid, either internally or externally from the cylinder boot. Stalling can also happen if there is a brake line obstruction, either by a chunk of rust or a pinched brake line. Air in the brake fluid from a hole in the system can prevent proper pressure to the brakes
Title: Re: tj question
Post by: willo on September 01, 2012, 09:25:38 PM
had a bit of an issue bleeding it today if thats any help :017:

it did this stalling after braking at kov too

so what are the tests to proove or disproove stuff?
Title: Re: tj question
Post by: Cockney Boy on September 01, 2012, 09:32:59 PM
What was the problem with bleeding the brakes?
Title: Re: tj question
Post by: willo on September 01, 2012, 09:39:39 PM
What was the problem with bleeding the brakes?

well they still aren't bled properly but work enough to do, but anyhow we bled the brakes all round and yet i still have a squishy pedal, there was clear fluid at all 4 corners. I also have a line lock solenoid plumbed into the rear line before it tees off, which from memory is normally open.

with the line lock on I can feel the pedal firm up, but as soon as i switch it off the pedal nearly drops to the floor
Title: Re: tj question
Post by: Cockney Boy on September 01, 2012, 09:49:06 PM
I had exactly the same problem on my dads car last year. it turned out to be the servo, it looked ok but chnaged it for a new one and no more problem.
Title: Re: tj question
Post by: Panic mechanic! on September 01, 2012, 10:11:50 PM
 :iagree:
Title: Re: tj question
Post by: willo on September 01, 2012, 10:27:46 PM
is the servo the mc?
Title: Re: tj question
Post by: Lornaben on September 01, 2012, 10:39:54 PM
is the servo the mc?
MC bolts to the servo. The servo is the big black canister between the bulkhead and MC with the vacuum pipe plumbed to it.
Title: Re: tj question
Post by: willo on September 01, 2012, 10:48:44 PM
Thanks. Every day is a school day  :greggmo:
Title: Re: tj question
Post by: wildwood on September 01, 2012, 10:57:48 PM
master Power brakes..... Big feck off servo from the Land of the septics....... Got one on the YJ turned an MOT failure on 35 s into  a good stopper ..

If ya come to CF..... Tis under my hood :icon_biggrin: :icon_twisted:
Title: Re: tj question
Post by: isle of man on September 02, 2012, 02:13:54 AM
Had the same problem hydro boost was the answer,
Title: Re: tj question
Post by: Delk on September 02, 2012, 10:36:07 AM
A soft brake pedal is common on TJ's after you install large front brakes. You now require more fluid for your full sized calipers and this is nomally just on the edje for a stock MC.

Do a quick search on the Pirate and you should find details on other master cylinders with a slighly larger bore so they push more oil.

My pedal is quite soft but I am used to it. I have a new MC from Dodge truck I just dug out that will be going on when I get home.

Title: Re: tj question
Post by: isle of man on September 02, 2012, 11:23:19 AM
The Dodge Master Cylinder is useless have one here Gasser fitted for me gathering dust!!!
Title: Re: tj question
Post by: wildwood on September 02, 2012, 12:02:05 PM
some guys on Pirate have had success with the E250 MC........(is that a Dodge...? dunno?) but there you go.....

My MC on the Master power brakes is Kin huge and has same size res for both front and rear so discs not a prob....

HOWEVER!!!!! with the monster size of the 1 Ton fronts and 3/4 ton rears the pedal still goes half way down before locking as solid as a solid thing. would fail a MOT.....but those days are behind me :icon_twisted:

reckon Hydroboost as IOM said is the way forward...... Done right you could lock 40's on a dry road......Nice :icon_biggrin:
Title: Re: tj question
Post by: willo on September 02, 2012, 02:29:05 PM
this is all a bit odd, the brakes bar the stalling were fine, then yesterday we replaced a brake line on the rear, and after trying to bleed it, i have had a squidgy pedal since.

I have an ssbc kit on the rear so may have uprated parts anyhoo??
Title: Re: tj question
Post by: wildwood on September 02, 2012, 02:47:41 PM
If ya got any other hydro stuff in the brake system open it up ....... blead brakes as normal then if poss blead the hand brake if hydro or line lock..... this is what `I had to do with my hydro handbrake on the 1 Ton could hear air coming out as cranked the handle...... then go back and blead again. as normal.......

Don't know if this is correct procedure but worked for me.
Title: Re: tj question
Post by: Mike Pavelin on September 02, 2012, 05:41:43 PM
This is a bit cofusing. Do you have a problem with engine stalling, brake performance or both?

If you think the brake servo is causing the engine to stall, disconnect the vacuum line at the engine, plug the manifold and see if it still stalls, be careful cos you won't have power brakes.
Title: Re: tj question
Post by: willo on September 02, 2012, 07:07:20 PM
Both!
Title: Re: tj question
Post by: MOCAJ on September 02, 2012, 07:58:12 PM
if your ssbc conversion has been done to the book you will have a larger master cylinder, its that big it virtually touches your airbox

and the innards will be stripped out of the proportioning valve given you equal braking fore and aft  :greggmo:
Title: Re: tj question
Post by: willo on September 02, 2012, 08:07:16 PM
airbox? :eusa_think:
Title: Re: tj question
Post by: MOCAJ on September 02, 2012, 08:09:18 PM
only trying to help dood, can measure my m/c if it helps any  :icon_winkle:
Title: Re: tj question
Post by: willo on September 03, 2012, 08:30:09 AM
no worries, thanks yes that'd be a help!
Title: Re: tj question
Post by: willo on September 03, 2012, 11:33:01 PM
so after getting my castor angle a bit better tonight and a remarkable change in the steering, I moved onto brakes. I molegripped the vacuum pipe down and went for a drive, the pedal was as hard as a hard thing, but yet the car kept stalling on braking.

This will probably sound like a stupid question, but would the sensor that is in the cat have anything to do with it??

If I can get this niggle sorted I will come up to cheapfest, I have booked the friday off..... :greggmo:
Title: Re: tj question
Post by: donk498 on September 03, 2012, 11:45:39 PM
When you say its stalling when braking, is it cutting out as soon as you press the brake pedal or as you come to a stop? Oh and is it auto or manually, i forget?
Title: Re: tj question
Post by: willo on September 04, 2012, 12:13:09 AM
As i try and come to a stop. Its a manual

Bear in mind the tryck hasn't really run for most of the year
Title: Re: tj question
Post by: Cockney Boy on September 04, 2012, 06:30:42 AM
Mine always stalls when I'm in Low ratio just as I'm pulling up but it's never done it in 2W or 4WH
Title: Re: tj question
Post by: Ezz on September 04, 2012, 08:38:06 AM
have you tried increasing the tickover speed a tad?

mine stalled a couple off times, so i turned the tickover up a bit, seemed a lot better...

Title: Re: tj question
Post by: willo on September 04, 2012, 11:17:33 AM
Yuh there is also food for thought that its the extra load of the 24v alternator that is causing it to stall
Title: Re: tj question
Post by: wildwood on September 04, 2012, 11:37:08 AM
You don't make life easy for yourself Mr Willo?

you have gone seriously in at the deep end on this build...... Hats off to you tho....... You will eventually have a rig to beat those pesky Italians :icon_super:
Title: Re: tj question
Post by: bigjeepzj on September 04, 2012, 11:48:23 AM
I'v got a long arm kit on my ZJ and i it work due to having a long wheel base.
I can see your point on a TJ that it may not be the est idea
But there's not a lot u can do to a ZJ body to move it out of the way and keep it road legal  :lol_hitting:
Title: Re: tj question
Post by: willo on September 04, 2012, 11:49:47 AM
Not hugely in at the deepend. Then again when you start something new your learning curve is liable to be pretty steep, Not bothered about beating the italians, i just want something I can enjoy and that will hold up to a challenge event. Rhe jeep is awesome, just gotta iron out the niggles :greggmo:
Title: Re: tj question
Post by: bgbazz on September 04, 2012, 02:44:41 PM
Will, did you try the tip from Ezz? Boost the idle speed by 100rpm and see what happens..lumpy, modified lumps often have idling problems.
Title: Re: tj question
Post by: willo on September 04, 2012, 03:03:41 PM
When i get back from work i will give it a go, but i have a kunkle to change first and some propshafts to grease  :003:
Title: Re: tj question
Post by: willo on September 04, 2012, 08:57:37 PM
Right so. Fitted hi steer kunkle and arm tonight. Also upt the idle speed. Not sure if its the castor or the arm or both but it has made a hell of a difference and i am now confident to drive it on the road over distances. Its not that rolly either and doesnt stall anymore. So all good. :icon_super: Hopefully i can get my brakes bled properly, and some
Axle
Breathers fitted. ( may have to go on the covers)

I think i owe it to birtys to turn up at cheapfest as without it, none of this woulda happened :003:
Title: Re: tj question
Post by: bgbazz on September 05, 2012, 05:08:58 AM
 :icon_super:  Result.
Title: Re: tj question
Post by: Ezz on September 05, 2012, 07:57:46 AM
Well done that man :icon_super:
Title: Re: tj question
Post by: MOCAJ on September 05, 2012, 06:58:10 PM
no worries, thanks yes that'd be a help!

sorry, its 7 1/2" long from the servo to the end of the master cylinder, as i said touches my airbox

you can have a look at the weekend tho  :icon_winkle:
Title: Re: tj question
Post by: willo on September 05, 2012, 09:42:02 PM
well after todays visit to bonnet up engineering (my drive) all I have to say is squarky birds  :icon_twisted:
Title: Re: tj question
Post by: MOCAJ on September 06, 2012, 07:25:00 AM
front prop or idler pulleys ?
Title: Re: tj question
Post by: willo on September 06, 2012, 07:31:17 AM
Rear prop which is a cut down front prop
Title: Re: tj question
Post by: MOCAJ on September 06, 2012, 07:36:44 AM
get the grease gun out Will
Title: Re: tj question
Post by: willo on September 06, 2012, 08:08:20 AM
get the grease gun out Will

yup its full of it, rebuild next month me thinks!
Title: Re: tj question
Post by: isle of man on September 06, 2012, 08:58:36 AM
Rear prop which is a cut down front prop


 :hysterical:
Title: Re: Re: tj question
Post by: Dave69 on September 06, 2012, 07:54:15 PM
Brake assist check. Engine off - repeatedly press and depress the brake pedal until it is solid then start the engine, pedal should drop slightly and thats it. If it drops to the floor then servo needs overhaul or repair
Title: Re: tj question
Post by: Delk on September 06, 2012, 08:39:40 PM
You should not be able to adjust the idle speed on a TJ since this is done by the ECM and the idle speed valve. If you adjust the little stop screw under the throttle plate the idle valve should compensate by moving in and out. This valve gets dirty sometimes and may need cleanging?? Just an idea.

Also do you have a speedo cable hooked up to your Dana 300? I think the ECM gives the engine a little bit extra rpms until it senses a stops. Maybe way off but I remember reading something along that line a long time ago.
Title: Re: tj question
Post by: willo on September 06, 2012, 09:21:33 PM
Rear prop which is a cut down front prop


 :hysterical:

whats so funny about that ghay boi? it works and didn't cost me a fortune
Title: Re: tj question
Post by: willo on September 06, 2012, 09:24:37 PM
You should not be able to adjust the idle speed on a TJ since this is done by the ECM and the idle speed valve. If you adjust the little stop screw under the throttle plate the idle valve should compensate by moving in and out. This valve gets dirty sometimes and may need cleanging?? Just an idea.

Also do you have a speedo cable hooked up to your Dana 300? I think the ECM gives the engine a little bit extra rpms until it senses a stops. Maybe way off but I remember reading something along that line a long time ago.

this all sounds like sense, many thanks! i adjusted the idle by shortening the length of my hand throttle. speedo cable, no, not sure how i'll get round that one as its an early d300 with mechanical speedo cable...
Title: Re: tj question
Post by: bgbazz on September 06, 2012, 09:27:55 PM
I know most of you think I'm a thick prick..but WTF is a kuncle?
Title: Re: tj question
Post by: willo on September 06, 2012, 09:31:59 PM
I know most of you think I'm a thick prick..but WTF is a kuncle?

(https://birtydastards.com/frm/proxy.php?request=http%3A%2F%2Fwww.pirate4x4.com%2Ftech%2Fbillavista%2FSteering%2FSteering_1%2Fsteering12.jpg&hash=8685d1a23f9c86593f55815cbc10309288e96d3f)
Title: Re: tj question
Post by: JamesH on September 06, 2012, 09:50:21 PM
I have front prop as rear too, never caused me any problems
Title: Re: Re: tj question
Post by: willo on September 06, 2012, 09:59:55 PM
Brake assist check. Engine off - repeatedly press and depress the brake pedal until it is solid then start the engine, pedal should drop slightly and thats it. If it drops to the floor then servo needs overhaul or repair

thanks, presumably with my line lock open?
Title: Re: tj question
Post by: Delk on September 06, 2012, 10:06:06 PM
If you look you will probably find several outfits that make speedo adapter kits for a d300. Its a good chance is your issue. I did a lot of research into the fuel system when I built my stroker and after when I was looking into supercharging it and I seem to remember idle and speed were related.

The front drive shaft uses the same 1310 cv as the standard custom rear shafts so thats an excellent idea.
Title: Re: tj question
Post by: JamesH on September 07, 2012, 09:32:12 AM
The tube thickness is the same as the Tom Woods shafts and for an XJ it doesn't need to be cut down
Title: Re: tj question
Post by: willo on September 07, 2012, 10:18:10 AM
The tube thickness is the same as the Tom Woods shafts and for an XJ it doesn't need to be cut down

mine is cut down from the TJ front length, bt not as short as a TJ rear as I am now at about 105" wheelbase....i think!