I bought a power steering pump and the plastic return fitting broke as I just started the line onto it. Emailed RockAuto and they gave me complete credit, sent another one and I did not have to return the other one. Pretty easy for me. I think the fitting was weak or cracked by the way it looked after breakage. I was impressed.I bought a replacement radiator plastic tank from Rock Auto 3 years ago. It recently cracked across the top. Called Rock back, they sent replacement and pre-paid shipping label to return the old one for a full credit. Part had a lifetime guarantee.