Just put a new radiator in my 87 Cherokee. When I started it up, I found another problem, the reservoir was overflowing. The jeep isn't overheating so I know that's not the problem and there are no visible leaks. Pressure is coming up and pushing the water out. The hose going into the radiator isn't getting any pressure either. I thought it could be the head gasket but wouldn't water be leaking from the head? Anyway, I've been doing research and found out that the reservoir bottles are crap. I already replaced the radiator, water pump, and thermostat so it's too late to do a conversion. Can someone recommend a better bottle that won't give me anymore problems?

 

Replace the reservoir cap with a 703-1396 from Napa.

 

X2^^^ Once i replaced the cap it made a difference!!