Are these brake boosters interchangeable?

scottgraham

scottgraham

Just another bad habit
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Okay, so my kid's jeep has a leak at the master and probably screwed up the booster diaphragms. He is on a high school budget and looking at used. My quandary is this: His booster has a part number of 4798158 which is correct for the year, my TJ has a part number of 52009135, which are all over Ebay. Rock auto also calls for 4798158 for both jeeps. They are both '98's, mine is a 4.0, his a 2.5, I have cruise. The masters and brake boosters look identical from the outside. Anybody know if they swap?
THX!
 
scottgraham said:
Okay, so my kid's jeep has a leak at the master and probably screwed up the booster diaphragms. He is on a high school budget and looking at used. My quandary is this: His booster has a part number of 4798158 which is correct for the year, my TJ has a part number of 52009135, which are all over Ebay. Rock auto also calls for 4798158 for both jeeps. They are both '98's, mine is a 4.0, his a 2.5, I have cruise. The masters and brake boosters look identical from the outside. Anybody know if they swap?
THX!
Click to expand...
Perfectly interchangeable.
 
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So it finally wasn't raining today (over 4 inches last night) and thank dog it really hasn't snowed this year.
He (we) finally got the used part in, and in his Jeep. It appears the piston on the brake booster on the 52009135 has a little shorter throw than the 4798158 because his brake lights were on when brakes were off. We (I) made a shim for the pedal shaft to hit the switch so it doesn't drain the battery. We haven't bled it yet, the rear (brake) zerks were really rusty so I told him to spray them for a couple of days cause we didn't want one of those breaking off...because then we (I) would have to extract/ drill/ tap/ thread a new one in.
Next we're on to his power steering leak....at least that one for now we can just keep topping off.

He wants to LS swap it...I just want to keep it on the road for now...and safe(ish).
 
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Glad you got it taken care of.

Just tell him to swap in an LS7 and be done with it :ROFLMAO:
 
scottgraham said:
So it finally wasn't raining today (over 4 inches last night) and thank dog it really hasn't snowed this year.
He (we) finally got the used part in, and in his Jeep. It appears the piston on the brake booster on the 52009135 has a little shorter throw than the 4798158 because his brake lights were on when brakes were off. We (I) made a shim for the pedal shaft to hit the switch so it doesn't drain the battery. We haven't bled it yet, the rear (brake) zerks were really rusty so I told him to spray them for a couple of days cause we didn't want one of those breaking off...because then we (I) would have to extract/ drill/ tap/ thread a new one in.
Next we're on to his power steering leak....at least that one for now we can just keep topping off.

He wants to LS swap it...I just want to keep it on the road for now...and safe(ish).
Click to expand...
No, it doesn't have a shorter throw. You likely bumped the brake light switch with the brake pedal and shortened the adjuster. Remove the shim, grab the plunger with a pair of needle nose pliers, pull it outward and it will ratchet longer. Release the brake pedal and it will push the plunger in to the correctly adjusted length. ;)
 
Update.
Appears now there is a clog in the rear lines, neither will bleed. We bench bled the MC, it was fine, had pressure below the proportional valve also...had the boy bleed the front, they were fine, took out the bleeders in the back and cleaned them up. No love. My guess is he didn't have rear brakes to begin w/. I've done this once over 20 years ago, non-jeep, so do I snake a wire or just replace brake likes? Or could it be the rear pistons locked up?
Break, fix, repeat.
 
Last edited:
scottgraham said:
Update.
Appears now there is a clog in the rear lines, neither will bleed. We bench bled the MC, it was fine, had pressure below the proportional valve also...had the boy bleed the front, they were fine, took out the bleeders in the back and cleaned them up. No love. my guess is he didn't have rear brakes to begin w/.
Break, fix, repeat.
Click to expand...
Are you bleeding with the key on and parking brake off so you can watch to see if the brake light turns on?
 
Parking brake was off. Key not on, I don't know if his brake light even works.
So funny thing...I was letting the boy do this and his friends were helping...I finally got under it today in the wet driveway and low and behold, the driver rear axle line had rusted through and severed...I ordered stainless tonight.
:rolleyes:
 
Rear axle lines came in and went ahead and replaced the rear center as well.
It was only 24 deg this morning, but we knocked it out!
Thanks again for all the help Blaine and Chris!
 
Bruno David said:
May I ride on this interchanging topic and ask if the XJ brake booster will fit/work on a 1997 TJ?

Thanks
Click to expand...

XJ on top. Wrangler below. (it is upside down) The push rod is different. Everything else is the same.
1598792921745.png


1598793083757.png
 
Are the 99 TJ & 99 XJ Brake booster check valves the same - part numbers are different but look the same on the outside but dont know if on the inside they are different - what other brake booster check valves can I use - such as GM , etc.
 
Can I ride this topic aswell? I have a 98 tj with a ls swap on 43s and one tons. I built the Jeep with one tons, a 98 tj brake booster and a 2005 dodge 2500 master cylinder and drove it for about a year and everything worked fine until I did the ls swap. I’m getting a stiff pedal and can’t stop The jeep in 4 low. I read above and I need to turn the idle down on the Holley ecu but is this the only problem that will Cause a stiff pedal?

I tried spraying starter fluid everywhere around the vacuum lines and I’m not getting any idle Up so I don’t think it’s a vacuum leak.
 
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